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Your statement is too broad to be taken seriously.
If you have a 700W PSU with four +12V rails rated at 18A each, and the +12V combined is rated at 54A (648W) then there is no trapped power as the sum of your rails is greater than the actual +12V capability of the PSU.
If you aren't using all of the rails of a PSU, let's say you only use 2 of 4 or 3 of 4, for example, then there may be trapped power... but you're also using a PSU of greater capability than what you actually need. For example: A PSU with four PCIe connectors across two dedicated +12V rails, but the PC doesn't use SLI or doesn't even have graphics cards that utilize PCIe power connectors. Yes, the +12V rail can only deliver what is demanded of it, but if you don't even have the components to demand that power, then the argument is moot.
Google? Newegg? It's easier to find units with split +12V than not. The FSP in your sig, for example, has split +12V rails. Every OEM other than Seasonic splits up their +12V rails. When you see something like an Andyson (like an Ultra X3) or Channel Well (like a Corsair), etc. with one +12V rail, it's usually because the company branding that unit asked that the OCP circuit board be removed and the output circuit points jumpered together. This saves money and is easy to market as an "advantage" so it's commmonly done.... but it's the exception, NOT the rule.
Replace "many" with "few". VERY few. A handful of Topower units with "Rail Fusion" may or may not have slit +12V rails, Antec True Power Trio, most Antec Earth Watts and the Corsair HX Series. The last three are both the same OEM (Seasonic) and AFAIK the companies using that OEM didn't even realize that these PSU's did not in fact have split rails and OCP. Antec has actually just recently released "D" versions of the Earth Watts that are essentially the same units, but with the split +12V rails.
I just noticed you ended up buying a Ultra X-pro 600 for $50. I did some research and most reviews give it a thumbs up.
It's got to be about the best PSU you can get for $50. Of course I like the single 12v rail. I almost ordered one my self to replace the undersized PSU used in the rig in my sig. The PSU I have works fine but I want to go quad core and it will never handle it.
What stopped me from buying the Ultra X-pro 600. It's rated at 25C not 40C or 50C so at extremes it may have half its rated output available. Its 12v output of 36 amps is lower than many PSU's around 600 watts. The Corsair HX520W, 12v is 40 amps at 50C. The Corsair HX620W, 12v is 50 amps at 50C. The PCP&C Silencer 610 EPS, 12v 49 amps at 40C. I also dislike the fact that some heat from the PSU is vented back into the case which could raise case temp.
The Ultra X-pro 600 is sure a step up from what I have and should run your rig fine. My rig has one less HD but my CPU most likely draws more power. You may even be able to run 2 8800 GT's in SLI. The big question will be case cooling because the 8800 GT's will be pumping a lot of heat into your case so it will be hard to keep your case temp at or below 25C. Anything over 25C will decrease your PSU's output, the hotter the temp the smaller the PSU will become.
It's got to be about the best PSU you can get for $50. Of course I like the single 12v rail. I almost ordered one my self to replace the undersized PSU used in the rig in my sig. The PSU I have works fine but I want to go quad core and it will never handle it.
What stopped me from buying the Ultra X-pro 600. It's rated at 25C not 40C or 50C so at extremes it may have half its rated output available. Its 12v output of 36 amps is lower than many PSU's around 600 watts. The Corsair HX520W, 12v is 40 amps at 50C. The Corsair HX620W, 12v is 50 amps at 50C. The PCP&C Silencer 610 EPS, 12v 49 amps at 40C. I also dislike the fact that some heat from the PSU is vented back into the case which could raise case temp.
The Ultra X-pro 600 is sure a step up from what I have and should run your rig fine. My rig has one less HD but my CPU most likely draws more power. You may even be able to run 2 8800 GT's in SLI. The big question will be case cooling because the 8800 GT's will be pumping a lot of heat into your case so it will be hard to keep your case temp at or below 25C. Anything over 25C will decrease your PSU's output, the hotter the temp the smaller the PSU will become.
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Of course, $50 has to be below cost. The MSRP on it on Ultra's site is $129.99. Maybe they're liqudating to help pay for their modular patent lawsuit.
Wow.. where do you get your mis-information from. Not to pick on you, but first the whole "trapped power that you have to balance" nonsense about split +12V rails and now this. The Ultra is rated at 40°C and even if it was rated at 25°C it wouldn't only be able to put out half of it's rated wattage. The number is typically around the neighborhood of 75%.
He could easily run two GT's regardless of how hot it gets in his case. It would be impossible to get your case temps down to 25°C because that's room temperature. But like I said, the X-Pro is rated at 40°C and even it was rated at 25°C it would be able to put out around 450W continuous... theoretically speaking of course.
I see the 700 watt 4 rail PSU you spun up looks quite nice. Does anyone make a PSU with these spec's? Can you give some examples of some smaller PSU's that still get round load balancing and trapped power problems? Say a 500 watt PSU with around 36 amps for the 12 volt as most people will never need a larger PSU. If you go 3 18 amp rails you will lessen trapped amperage. 2 rails? How would you pin out this PSU?
400 and 600 watt PSU's may be even tougher to eliminate possible problems?
Whats funny to me is it does not even follow the the 240 VA rule so why bother having split rails in the first place. The 240 VA was set for safety nothing more so this PSU is 2 faced.
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600W and up aren't hard to find with four +12V rails and making four +12V rails easily eliminates "trapped power" scenario. There are even 550W PSU's with four +12V rails. But when you get to 500W and less, I agree that one should consider nothing but a single +12V rail PSU. Splitting into two hardly makes sense because there's usually relatively so little power on the +12V anyways, it's not going to take much for a short to overload the total +12V capability of the PSU. Ironically, the ATX12V only gives examples of PSU's up to 450W.
Having the OCP's set at higher than 240VA is a good comprimise. It allows more power to the connector, again eliminating the "trapped power" scenario, while also providing some safety. Some safety is still better than no safety. I'm about to update the sticky with links to pictures of a PSU that DID have the 240VA limit, smoke a +12V lead and managed to shut down before things really started to have a melt down. It's not an uncommon scenario for me or other techs in the field. If there was no OCP at all, i.e. "single +12V rail", the problem shown would be much, much worse.
"He could easily run two GT's regardless of how hot it gets in his case. It would be impossible to get your case temps down to 25°C because that's room temperature. But like I said, the X-Pro is rated at 40°C and even it was rated at 25°C it would be able to put out around 450W continuous... theoretically speaking of course."
Well Ultra only states 25C. Overall they lack needed info as way too many PSU's do.
"MTBF > 100,000 Hours at Full Load,
110VAC and 25°C Ambient Condition"
http://www.ultraproducts.com/p...Path=548&productID=603
BTW my case temps never get much over 25C under any load. I do have adaptive case cooling. When under full load My PC is quite loud.
"Wow.. where do you get your mis-information from. Not to pick on you, but first the whole "trapped power that you have to balance" nonsense about split +12V rails and now this." followed by
"But when you get to 500W and less, I agree that one should consider nothing but a single +12V rail PSU. Splitting into two hardly makes sense because there's usually relatively so little power on the +12V anyways, it's not going to take much for a short to overload the total +12V capability of the PSU.
I never said that. I said split rail designs can cause problems that may need addressing. You can't fully recover trapped amperage as it can't be pulled for use by another rail on most multi rail supplies.
I like the step around on 500 watt or less supplies.
Its not that a single rail would be safe enough but rather a split rail design would be capable of having load balance issues and surely could have trapped power that if needed can't be used.
Now in your guide The splitting of the +12V rail.
"The bottom line is, for 99% of the folks out there single vs. multiple +12V rails is a NON ISSUE."
Most people on these forums are not average. Most people here need a quality PSU of no more than 500 watts in size. So 99% rule becomes much less than 99% and not the black and white picture you paint. Multi rail PSU's create possible problems that are not possible on a single rail designs. Sure you can eliminate most if not all problems with a high wattage split rail PSU but a smaller, quality single rail PSU could do the same job. So should we all buy 700 or higher wattage supplies with 4 or more rails to get around the problems that do not exist?
Now on the safety side.
"Having the OCP's set at higher than 240VA is a good comprimise. It allows more power to the connector, again eliminating the "trapped power" scenario, while also providing some safety. Some safety is still better than no safety. I'm about to update the sticky with links to pictures of a PSU that DID have the 240VA limit, smoke a +12V lead and managed to shut down before things really started to have a melt down. It's not an uncommon scenario for me or other techs in the field. If there was no OCP at all, i.e. "single +12V rail", the problem shown would be much, much worse."
Are you saying single rail PSU's have no OCP only multi rail PSU's do? I'd sure like to see a test run on the exact PSU that had the short in the 12 volt line to see if it really had functioning 240 VA OCP. What actually shorted, the cabling it self? If so I'd call that a dead short. 12 volts at very low resistance should draw enough amperage to cause OCP to kick in on even a high wattage single rail PSU. Or was this melting caused by a high resistance connection and not a short at all?
I can surely see the higher the amperage before OCP kicks in the more danger of fire exists if a partial short occurs. The the 240 VA limit per rail sounds like a nice safety feature. Trouble is most people only need a 500 watt or smaller PSU where multi rail PSU's have a greater chance of causing balance and trapped power problems that you claim do not exist. You think that this debate is black and white when its more a shade of gray.
I'd say the choices for 99% of the forum members would be.
For people more worried about safety. Go with a moderately sized multi rail supply with the possibility of balance and trapped amperage problems causing the need for a bigger PSU or buy a huge multi rail PSU to lessen or eliminate that possibility.
For people that just want to power their rig, for sure and maybe even like fire (slim ass chance BTW) buy a moderately sized single rail supply and be done with it.
Well Ultra only states 25C. Overall they lack needed info as way too many PSU's do.
"MTBF > 100,000 Hours at Full Load,
110VAC and 25°C Ambient Condition"
http://www.ultraproducts.com/p...Path=548&productID=603
BTW my case temps never get much over 25C under any load. I do have adaptive case cooling. When under full load My PC is quite loud.
"Wow.. where do you get your mis-information from. Not to pick on you, but first the whole "trapped power that you have to balance" nonsense about split +12V rails and now this." followed by
"But when you get to 500W and less, I agree that one should consider nothing but a single +12V rail PSU. Splitting into two hardly makes sense because there's usually relatively so little power on the +12V anyways, it's not going to take much for a short to overload the total +12V capability of the PSU.
I never said that. I said split rail designs can cause problems that may need addressing. You can't fully recover trapped amperage as it can't be pulled for use by another rail on most multi rail supplies.
I like the step around on 500 watt or less supplies.
Its not that a single rail would be safe enough but rather a split rail design would be capable of having load balance issues and surely could have trapped power that if needed can't be used.
Now in your guide The splitting of the +12V rail.
"The bottom line is, for 99% of the folks out there single vs. multiple +12V rails is a NON ISSUE."
Most people on these forums are not average. Most people here need a quality PSU of no more than 500 watts in size. So 99% rule becomes much less than 99% and not the black and white picture you paint. Multi rail PSU's create possible problems that are not possible on a single rail designs. Sure you can eliminate most if not all problems with a high wattage split rail PSU but a smaller, quality single rail PSU could do the same job. So should we all buy 700 or higher wattage supplies with 4 or more rails to get around the problems that do not exist?
Now on the safety side.
"Having the OCP's set at higher than 240VA is a good comprimise. It allows more power to the connector, again eliminating the "trapped power" scenario, while also providing some safety. Some safety is still better than no safety. I'm about to update the sticky with links to pictures of a PSU that DID have the 240VA limit, smoke a +12V lead and managed to shut down before things really started to have a melt down. It's not an uncommon scenario for me or other techs in the field. If there was no OCP at all, i.e. "single +12V rail", the problem shown would be much, much worse."
Are you saying single rail PSU's have no OCP only multi rail PSU's do? I'd sure like to see a test run on the exact PSU that had the short in the 12 volt line to see if it really had functioning 240 VA OCP. What actually shorted, the cabling it self? If so I'd call that a dead short. 12 volts at very low resistance should draw enough amperage to cause OCP to kick in on even a high wattage single rail PSU. Or was this melting caused by a high resistance connection and not a short at all?
I can surely see the higher the amperage before OCP kicks in the more danger of fire exists if a partial short occurs. The the 240 VA limit per rail sounds like a nice safety feature. Trouble is most people only need a 500 watt or smaller PSU where multi rail PSU's have a greater chance of causing balance and trapped power problems that you claim do not exist. You think that this debate is black and white when its more a shade of gray.
I'd say the choices for 99% of the forum members would be.
For people more worried about safety. Go with a moderately sized multi rail supply with the possibility of balance and trapped amperage problems causing the need for a bigger PSU or buy a huge multi rail PSU to lessen or eliminate that possibility.
For people that just want to power their rig, for sure and maybe even like fire (slim ass chance BTW) buy a moderately sized single rail supply and be done with it.
You keep going back to this "load balancing" argument. We have already said multiple times, there is no need to balance loads. If one 12V rail want to pul 17 Amps and the other rails want to pull 0 Amps then there is no problem in doing that.
Also no on most PSUs with "multiple rails" there is no trapped power. As already stated they start with a single transformer and then branch off from there and apply OCP to the splits. If the combined Amperage of a system designed like that (which is MOST of them) is 48 Amps and you split it into 4 "rails" with OCP limits of 18 Amps each. Then you can pull 18Amps from 12V1 18Amps from 12V2 12Amps from 12V3 and 0Amps from 12V4. Or you can pull 10 Amps from 12V1 10 Amps from 12V2 18Amps from 12V3 and 10 Amps from 12V4. There is no trapped power, it is there for all of the rails to use and a rail can use as much power as it needs up to its OCP limit and the 4 together can use as much as they need up to the PSU's combined 12V limit.
Yes there is no need to put OCP on a single rail system. If there is a short and the load keeps building then the PSU's own limitations will shut it down once it hits its MAX power draw.(if it doesn't catch on fire first)
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Learn to use the quote function of these forums and your posts will be much easier to read.
That's MTBF. MTBF rating is almost always at 25°C. MTBF does NOT always represent the temperature at which the unit is rated at.
Hmm.... What's your room temperature? 15°C (about 60°F). My wife would kill me if I kept the house below 20°C. And how are you getting these temps? Board sensor or actual thermometer?
Like HOOfan said, you keep going back to this argument.. like a crutch... which tells me that if you did read the FAQ, you didn't understand it.
Why thank you.
I never said I supported "single +12V rail" over "multiple +12V rail" in general or vise versa. I just hate to see someone go through life with ignorance and too stubborn to learn differently. There are good arguments FOR and AGAINST both single and +12V rail power supplies. But you have been so brain washed with FUD that your own opinion is based on lies and/or misconceptions and you refuse to believe the truth.
Single +12V rail is ideal for many applications. If a 450W PSU is adequate for someone, than the Corsair VX450W, a single +12V rail PSU, is probably the best option on the market. But with higher wattage units with 50A, 60A, 70A, etc. on the +12V rail, in my opinion having all of that on one, unlimted rail has potential hazards. Hazards that the IEC, UL and Intel felt were necessary to address. We've tried to explain and have given examples of how the whole "trapped power" idea is FUD and how there is truly no "load balancing" for a consumer to do (in reality the "load balancing" is done by the engineer before the product is even sold) and yet you still keep coming back to the same rhetoric.
It's like this: http://www.iamboredr.com/media..._-_Stubborn_As_A_Mule/
Once again: There's no "trapped power" in MOST cases and regardless of your PSU, there's no "load balancing" because all similar connectors are put on the same rail and/or get their own dedicated rail. How do you "load balance" when you need a Molex and all of your Molexes are on the same +12V rail? How do you "load balance" when you have two PCIe connectors each on their own +12V rail?
I never said that. But Anandtech is more of an enthusiast community than your typical Best Buy shopper and people ARE buying the higher wattage units.. even if they don't NEED the higher wattage... and some of those people think they need a single +12V rail because of "load balancing" and "trapped power". If they're running a high end graphics card (single PCIe power connector) not running SLI, they could use virtually ANY PSU around the 450W to 500W range and be FINE. But on that same note, it SHOULD NOT matter if the PSU has one or two +12V rails because if they only have the one card, probably a couple hard drives, etc. then the 18A or 20A or whatever on the +12V that's supplying power to everything other than the CPU is STILL enough power. And since most single +12V rail PSU's don't have any kind of OCP, it might still be prudent to get a split +12V rail PSU... on the other hand, if they were over-taxing the PSU in the first place, they'd figure that out before any thing "hazardous" requiring an OCP would occur.
If the person is running SLI or has an Ultra or GX2, etc., then I agree they're not the norm. They could use a 550W, and a single +12V rail would be best there since 4x +12V rail are hard to find and a 2x +12V rail could be admittingly problematic, but if they get something that's 600W and up, which I personally think would be a wiser choice for SLI, etc., then MOST of the product on the market IS 4x +12V rail.
Are you serious? Are you really serious because what you just said in that paragraph, and hopefully I'm just misunderstanding you, tells me that you skimmed the FAQ and still don't know how multiple +12V rails work.
Let me recap... Maybe this time you'll get it.....
Multiple +12V rails typically are not multiple +12V rails. They take one +12V rail and split it up into multiple circuits we call "rails". Each of these circuit has an OCP installed that trips the PSU off when a rail is overloaded. A PSU with a "single +12V rail" does not have this split and in most cases doesn't even have an OCP at the top end. Typically the +12V rating is just a "reasonable assessment" of how much DC power can be delivered by the PSU before it overheats or blows a fuse or just blows a rectifier. So in the case of a short, assuming that the it doesn't eventually trip the SCP, the PSU may not shut off at all.
See.. you keep making these generalizations.
Whether or not "500W is adequte for 99% of forum members" is debatable. A whole other discussion. And certainly the argument that most forum members only have a 500W PSU is debatable as well. Your biggest problem is with generalizations. You have all of these assumptions in your head and you apply them to everything. You even assumed that I'm some "multi +12V rail nazi" and then called it a "side step" when I said a single +12V rail PSU would be a good idea for most people. You kicked this whole thing off with generalizations like "multiple +12V rail PSU's have trapped power and require load balancing".
Again with the "load balancing" and "trapped amperage" argument. Let me ask you something... that FSP in your sig has two +12V rails. Have many "load balancing" or "trapped amperage" problems currently? You complained earlier that you THINK you can't upgrade to a quad core because you think your PSU is holding you back. Probably because of all of the FUD stuck in your head. Well let's take a look at this... you have 14A supplying power to everything but your CPU. Obviously that's working right now, right? You haven't talked about plans to upgrade the 8800 GT you're using, or more drives or anything that might require more power on the +12V1, so I think it's safe to assume that this rail is pretty good where it's at, right? You have 13A going to your current CPU. Way more than it really needs and definitely a fine example of "trapped power". But still... do you think you need more than than 156W for a quad core processor? Seriously. I'd be willing to bet money that if that PSU is powering what you have now without issue, you could upgrade your CPU to virtually ANYTHING and not have a problem... even though it's only a 450W and has split +12V rails.
I've already said that < 500W single +12V rail is fine, but let's assume I never said that. You have the opportunity to prove me wrong with your current build, with your current PSU, and an upgrade you had planned to do anyways. Why not find out if you really will have problems due to "trapped amperage" or "load balancing".
That's MTBF. MTBF rating is almost always at 25°C. MTBF does NOT always represent the temperature at which the unit is rated at.
Hmm.... What's your room temperature? 15°C (about 60°F). My wife would kill me if I kept the house below 20°C. And how are you getting these temps? Board sensor or actual thermometer?
Like HOOfan said, you keep going back to this argument.. like a crutch... which tells me that if you did read the FAQ, you didn't understand it.
Why thank you.
I never said I supported "single +12V rail" over "multiple +12V rail" in general or vise versa. I just hate to see someone go through life with ignorance and too stubborn to learn differently. There are good arguments FOR and AGAINST both single and +12V rail power supplies. But you have been so brain washed with FUD that your own opinion is based on lies and/or misconceptions and you refuse to believe the truth.
Single +12V rail is ideal for many applications. If a 450W PSU is adequate for someone, than the Corsair VX450W, a single +12V rail PSU, is probably the best option on the market. But with higher wattage units with 50A, 60A, 70A, etc. on the +12V rail, in my opinion having all of that on one, unlimted rail has potential hazards. Hazards that the IEC, UL and Intel felt were necessary to address. We've tried to explain and have given examples of how the whole "trapped power" idea is FUD and how there is truly no "load balancing" for a consumer to do (in reality the "load balancing" is done by the engineer before the product is even sold) and yet you still keep coming back to the same rhetoric.
It's like this: http://www.iamboredr.com/media..._-_Stubborn_As_A_Mule/
Once again: There's no "trapped power" in MOST cases and regardless of your PSU, there's no "load balancing" because all similar connectors are put on the same rail and/or get their own dedicated rail. How do you "load balance" when you need a Molex and all of your Molexes are on the same +12V rail? How do you "load balance" when you have two PCIe connectors each on their own +12V rail?
I never said that. But Anandtech is more of an enthusiast community than your typical Best Buy shopper and people ARE buying the higher wattage units.. even if they don't NEED the higher wattage... and some of those people think they need a single +12V rail because of "load balancing" and "trapped power". If they're running a high end graphics card (single PCIe power connector) not running SLI, they could use virtually ANY PSU around the 450W to 500W range and be FINE. But on that same note, it SHOULD NOT matter if the PSU has one or two +12V rails because if they only have the one card, probably a couple hard drives, etc. then the 18A or 20A or whatever on the +12V that's supplying power to everything other than the CPU is STILL enough power. And since most single +12V rail PSU's don't have any kind of OCP, it might still be prudent to get a split +12V rail PSU... on the other hand, if they were over-taxing the PSU in the first place, they'd figure that out before any thing "hazardous" requiring an OCP would occur.
If the person is running SLI or has an Ultra or GX2, etc., then I agree they're not the norm. They could use a 550W, and a single +12V rail would be best there since 4x +12V rail are hard to find and a 2x +12V rail could be admittingly problematic, but if they get something that's 600W and up, which I personally think would be a wiser choice for SLI, etc., then MOST of the product on the market IS 4x +12V rail.
Are you serious? Are you really serious because what you just said in that paragraph, and hopefully I'm just misunderstanding you, tells me that you skimmed the FAQ and still don't know how multiple +12V rails work.
Let me recap... Maybe this time you'll get it.....
Multiple +12V rails typically are not multiple +12V rails. They take one +12V rail and split it up into multiple circuits we call "rails". Each of these circuit has an OCP installed that trips the PSU off when a rail is overloaded. A PSU with a "single +12V rail" does not have this split and in most cases doesn't even have an OCP at the top end. Typically the +12V rating is just a "reasonable assessment" of how much DC power can be delivered by the PSU before it overheats or blows a fuse or just blows a rectifier. So in the case of a short, assuming that the it doesn't eventually trip the SCP, the PSU may not shut off at all.
See.. you keep making these generalizations.
Whether or not "500W is adequte for 99% of forum members" is debatable. A whole other discussion. And certainly the argument that most forum members only have a 500W PSU is debatable as well. Your biggest problem is with generalizations. You have all of these assumptions in your head and you apply them to everything. You even assumed that I'm some "multi +12V rail nazi" and then called it a "side step" when I said a single +12V rail PSU would be a good idea for most people. You kicked this whole thing off with generalizations like "multiple +12V rail PSU's have trapped power and require load balancing".
Again with the "load balancing" and "trapped amperage" argument. Let me ask you something... that FSP in your sig has two +12V rails. Have many "load balancing" or "trapped amperage" problems currently? You complained earlier that you THINK you can't upgrade to a quad core because you think your PSU is holding you back. Probably because of all of the FUD stuck in your head. Well let's take a look at this... you have 14A supplying power to everything but your CPU. Obviously that's working right now, right? You haven't talked about plans to upgrade the 8800 GT you're using, or more drives or anything that might require more power on the +12V1, so I think it's safe to assume that this rail is pretty good where it's at, right? You have 13A going to your current CPU. Way more than it really needs and definitely a fine example of "trapped power". But still... do you think you need more than than 156W for a quad core processor? Seriously. I'd be willing to bet money that if that PSU is powering what you have now without issue, you could upgrade your CPU to virtually ANYTHING and not have a problem... even though it's only a 450W and has split +12V rails.
I've already said that < 500W single +12V rail is fine, but let's assume I never said that. You have the opportunity to prove me wrong with your current build, with your current PSU, and an upgrade you had planned to do anyways. Why not find out if you really will have problems due to "trapped amperage" or "load balancing".
I think what wonderwrench is trying to say about trapped amps is this...
hypothetically, let's say you have a two rail 12V supply with 18A per rail. You apply a 12A load to each rail, leaving 6A free on each rail. Then you want to connect another device that wants to draw 10A. You can't because although your PSU is capable of outputting another 12A, it is only capable of outputting 6A more on each rail. So 6A is "trapped" on each rail.
I understand your argument, I think we all do, we are just saying that with proper planning it shouldn't be an issue. With bad planning, you can run into problems no matter what kind of PSU you buy.
hypothetically, let's say you have a two rail 12V supply with 18A per rail. You apply a 12A load to each rail, leaving 6A free on each rail. Then you want to connect another device that wants to draw 10A. You can't because although your PSU is capable of outputting another 12A, it is only capable of outputting 6A more on each rail. So 6A is "trapped" on each rail.
I understand your argument, I think we all do, we are just saying that with proper planning it shouldn't be an issue. With bad planning, you can run into problems no matter what kind of PSU you buy.
that isn't the impression I got by readin his theory about 6 Rails on the Coolermaster Real Power Pro
But with your example you are already using 288 Watts of 12V power, and you want to add another 120 Watt load to that? A PSU desinged like the one in your example is either a lower wattage 500W and bleow or a very poorly designed high wattage unit. So it might not be able to handle that type of load even if it were a single rail unit, not to mention that is a HUGE 12V only load.
Yes that was my original argument.
"My simple example. Just to keep it simple I will use a 2 rail supply. Each 12 volt rail can put out 18 amps for a total of 36 amps. 12V1 powers all but the CPU. 12V2 power only the CPU. Now say the CPU draws a max of 10 amps. You have 8 amps that can never be used, in affect de rating the PSU. This is not a show stopper but a single rail PSU can't have this problem. Now say 12V1 needs 20 amps to power the rest of your system. Guess what its not going to work because 12V1 is limited to 18 amps. If only the 8 amps trapped on 12V2 was available but its not."
As far as planing goes, much less research is needed using a single rail because they have less variables. If a single rail PSU can put out 40 amps at 12v guess what it can put out 40 amps. Many multi rail PSU's only list the amps available on each rail and not the combined 12v amperage or wattage available. Many multi rail supplies combined output is less than the sum of the 12v rails. This is done to lessen the tendency to trap power. Oh I forgot you can't have trapped power on a multi rail supply, duh.
It's never easy to pick a supply because of the lack of complete and accurate information.
Why add more bullshit to the mix, IMO it's not worth my time!
"jonnyGURU, That's MTBF. MTBF rating is almost always at 25°C. MTBF does NOT always represent the temperature at which the unit is rated at."
Ok I agree the 25C Ultra lists on their site is MTBF. Now show me the ambient temp they rate the supply at. How do you know if they do not say? To me it seems only higher end companies give you this info. I may be wrong again but my thinking is if they do not list the ambient temp its most likely 25C. This way the output is higher and allows the use of bad designs and or poor quality parts.
Also MTBF at 25C is a joke in its self.
"Hmm.... What's your room temperature? 15°C (about 60°F). My wife would kill me if I kept the house below 20°C. And how are you getting these temps? Board sensor or actual thermometer?"
My room temp is never more than 22C. My case cooling is quite good. 2 120 mm high CFM fans one in and one out. 1 92 mm high CFM side intake fan. Fan speeds are controlled by Speedfan. This setup is near silent at idle. Once loaded it's loud as hell. The only time this happens is when gaming in most cases so no big deal, to me anyway as I crank the audio quite high. Case temp is measured using a snapon digital thermometer placed in front of the CPU heat sink fans intake. This placement was done more for CPU cooler testing than measuring PSU inlet air temp so the actual inlet temp could be slightly higher.
"Again with the "load balancing" and "trapped amperage" argument. Let me ask you something... that FSP in your sig has two +12V rails. Have many "load balancing" or "trapped amperage" problems currently? You complained earlier that you THINK you can't upgrade to a quad core because you think your PSU is holding you back. Probably because of all of the FUD stuck in your head. Well let's take a look at this... you have 14A supplying power to everything but your CPU. Obviously that's working right now, right? You haven't talked about plans to upgrade the 8800 GT you're using, or more drives or anything that might require more power on the +12V1, so I think it's safe to assume that this rail is pretty good where it's at, right? You have 13A going to your current CPU. Way more than it really needs and definitely a fine example of "trapped power". But still... do you think you need more than than 156W for a quad core processor? Seriously. I'd be willing to bet money that if that PSU is powering what you have now without issue, you could upgrade your CPU to virtually ANYTHING and not have a problem... even though it's only a 450W and has split +12V rails.
I've already said that < 500W single +12V rail is fine, but let's assume I never said that. You have the opportunity to prove me wrong with your current build, with your current PSU, and an upgrade you had planned to do anyways. Why not find out if you really will have problems due to "trapped amperage" or "load balancing".
This is getting old so I'll finish this without re hashing all points on all sides. Lets talk about my PSU. First off this was I had it laying around when I built my latest rig so I gave it a try and it worked. With all previous builds of my main rig, K7 700 through K8 3000+ and about 7 years time I used a PCP&C Turbo Cool ATX 425. Cost me $200 and was well worth it IMO. This PSU was built before 12V was king and had no 4 pin P4 connector. I had PCP&C modify this supply when I got my first P4, no charge by the way. I could have used an adapter but its one more thing to f'up. This PSU had a 12v output rating of 15 amps. IMO this would not run my latest system. Now the FSP AX450-PN has 2 18 amp rails with 348 watts combined so 29 amps. This PSU runs my rig just fine as long as I do not over clock much past 3 Ghz. If I do I can get shut downs ( AKA like pulling the plug out of the wall) under extreme loading.
This could be a lack of quality on FSP part as they are not known for building the best PSU's. Its not temp related as I have good case cooling, and use a decent CPU cooler. I would guess FSP over rated this PSU or its a poor example. When and if I upgrade or build a bigger system I'm replacing the FSP regardless. I'd get another PCP&C Turbo Cool but they have nothing available between 510 and 860. The silencer is not the same beast. Might as well get a Corsair, Seasonic etc.
Lastly, if you read though your replies to me, you will see several times you contradict or sway from what you say in your guide.
Oh and I will have my Halon fire system ready by the time I get my new single rail PSU.
Ok I agree the 25C Ultra lists on their site is MTBF. Now show me the ambient temp they rate the supply at. How do you know if they do not say? To me it seems only higher end companies give you this info. I may be wrong again but my thinking is if they do not list the ambient temp its most likely 25C. This way the output is higher and allows the use of bad designs and or poor quality parts.
Also MTBF at 25C is a joke in its self.
"Hmm.... What's your room temperature? 15°C (about 60°F). My wife would kill me if I kept the house below 20°C. And how are you getting these temps? Board sensor or actual thermometer?"
My room temp is never more than 22C. My case cooling is quite good. 2 120 mm high CFM fans one in and one out. 1 92 mm high CFM side intake fan. Fan speeds are controlled by Speedfan. This setup is near silent at idle. Once loaded it's loud as hell. The only time this happens is when gaming in most cases so no big deal, to me anyway as I crank the audio quite high. Case temp is measured using a snapon digital thermometer placed in front of the CPU heat sink fans intake. This placement was done more for CPU cooler testing than measuring PSU inlet air temp so the actual inlet temp could be slightly higher.
"Again with the "load balancing" and "trapped amperage" argument. Let me ask you something... that FSP in your sig has two +12V rails. Have many "load balancing" or "trapped amperage" problems currently? You complained earlier that you THINK you can't upgrade to a quad core because you think your PSU is holding you back. Probably because of all of the FUD stuck in your head. Well let's take a look at this... you have 14A supplying power to everything but your CPU. Obviously that's working right now, right? You haven't talked about plans to upgrade the 8800 GT you're using, or more drives or anything that might require more power on the +12V1, so I think it's safe to assume that this rail is pretty good where it's at, right? You have 13A going to your current CPU. Way more than it really needs and definitely a fine example of "trapped power". But still... do you think you need more than than 156W for a quad core processor? Seriously. I'd be willing to bet money that if that PSU is powering what you have now without issue, you could upgrade your CPU to virtually ANYTHING and not have a problem... even though it's only a 450W and has split +12V rails.
I've already said that < 500W single +12V rail is fine, but let's assume I never said that. You have the opportunity to prove me wrong with your current build, with your current PSU, and an upgrade you had planned to do anyways. Why not find out if you really will have problems due to "trapped amperage" or "load balancing".
This is getting old so I'll finish this without re hashing all points on all sides. Lets talk about my PSU. First off this was I had it laying around when I built my latest rig so I gave it a try and it worked. With all previous builds of my main rig, K7 700 through K8 3000+ and about 7 years time I used a PCP&C Turbo Cool ATX 425. Cost me $200 and was well worth it IMO. This PSU was built before 12V was king and had no 4 pin P4 connector. I had PCP&C modify this supply when I got my first P4, no charge by the way. I could have used an adapter but its one more thing to f'up. This PSU had a 12v output rating of 15 amps. IMO this would not run my latest system. Now the FSP AX450-PN has 2 18 amp rails with 348 watts combined so 29 amps. This PSU runs my rig just fine as long as I do not over clock much past 3 Ghz. If I do I can get shut downs ( AKA like pulling the plug out of the wall) under extreme loading.
This could be a lack of quality on FSP part as they are not known for building the best PSU's. Its not temp related as I have good case cooling, and use a decent CPU cooler. I would guess FSP over rated this PSU or its a poor example. When and if I upgrade or build a bigger system I'm replacing the FSP regardless. I'd get another PCP&C Turbo Cool but they have nothing available between 510 and 860. The silencer is not the same beast. Might as well get a Corsair, Seasonic etc.
Lastly, if you read though your replies to me, you will see several times you contradict or sway from what you say in your guide.
Oh and I will have my Halon fire system ready by the time I get my new single rail PSU.
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You're assuming that the +12V combined capability of the PSU is 36A to begin with... which would be the exception, not the norm.
[/quote]
Same thing... That's assuming that this PSU has 36A available on the +12V and that it's evenly divided between two rails. Something that is an exception, not the norm.
Not "many". Only "some". In fact, very few and these PSU's are generally very, very cheap non-enthusiast grade units that try to "hide" the actual +12V capability and depend on someone's ignorance to come along and go: "12V1 + 12V2 = 12V capability... DONE!"
Not just many... MOST. MOST PSU's have +12V rails that, when added up, are greater than the actual capability of the +12V and that is so there is no trapped power.
Troll much? That was never said. I never said "you CAN'T have trapped power". I said it was the exception, not the norm and even used YOUR OWN PSU as an example of trapped power.
So you're too lazy to shop inteligently?
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I know it's 40°C because I know the Andyson unit of which the X-Pro 600W is based off of.
Agreed. But it's often used because it gives us higher MTBF numbers. The hours are lower almost exponentially when they use higher temps so you'll find that most MTBF at room temperature. Just like, as you point out, when they don't state at what temperature a PSU is rated at it's typically rated at 25°C, the same is true about MTBF.
That's very unusual to have in-case ambient temps that low, but if that's for real... good for you.
Fair enough. This is a part of your story that wasn't revealed before. But I think under "normal circumstances" if an AX-450 could run your rig with a dual core, it could run it with a quad core.
Proof?
In my "guide" I never try to sway one way or another. In fact, an earlier revision of my guide, either on my site or OCForums, I actually state the same thing I stated in this thread: Under 500W you might as well get a single +12V rail PSU. Although I can not find that quote right now, I'm fairly certain you can not find "contradictions" between what I posted in the "guide" and what I've posted in this thread. Primarily because, unlike you, I do not make generalizations.
I said: "for 99% of the folks out there single vs. multiple +12V rails is a NON ISSUE." I didn't say "for 99% of the folks out there multiple +12V rails is a NON ISSUE." and I didn't say "for 99% of the folks out there single +12V rail is a NON ISSUE." I said "for 99% of the folks out there single vs. multiple +12V rails is a NON ISSUE." That is to mean that this shouldn't be the first thing for someone to look at when buying a PSU. I then follow that up with the "more important things to look at when buying a PSU". You know... basic stuff like build quality.. having the correct connectors and/or number of connectors for my PC.. quietness, etc.
I would MUCH rather have a Gigabyte Odin 550W, for example, which happens to have four +12V rails, much more than an Ultra XVS 700W which only has one +12V rail. The Gigabyte is a FAR better PSU REGARDLESS of how many +12V rails it has.
Now by "99%" you could interpret that as "99% of users will need SO MUCH POWER that they would use a PSU that would tend to have four or more +12V rails (600W+)" and like I said, that whole "you can run your whole OC'd SLI machine off a good 300W PSU" is a whole other argument. A very tiring argument, but not this argument. And to counter that, I even used YOUR PSU as an example as how your "typical" non-SLI/Crossfire user could get by with YOUR power supply which not only has split +12V rails.... but a considerable amount of "TRAPPED POWER"!!! I never said "there's no such thing as trapped power" as a generalization, in fact in the "guide" I gave two examples of "trapped power".
Seriously... show me where I contradicted myself. And do so without quoting something out of context and then twisting into one of those "generalizations" you love to make so much yourself.
EDIT: And well played trolling there. You make a bunch of bogus statements based on generalizations, I tell you how you're wrong AND RIGHT, and then put me in a position of defending myself from accusations of "contradicting myself" by reiterating the points I made that SUPPORT your argument. Very well played indeed.
Ok, so my Ultra X-pro 600w arrived in the mail today and I'm getting a really strange issue.
I unplugged the ol' sp-500 and got the new ultra situated in my case. It took about 30 minutes to get everything nice. I then tried to power up the machine, and it did the usual p5n32-e sli plus motherboard thing where when it's been powered off for a long time, the voltages come up slowly. I don't know if it's a defect or if it's designed that way, but basically none of the fans or magneto-optical drives are on right away, then the fans slowly spin up, then the magneto-optical drives come on. About 15 seconds after you hit the power switch, finally you get video output and the POST screen. Except this time, it never posted.
I tried a jumper CMOS clear, and nothing. I tried removing the battery and unplugging the PSU for 30 minutes...twice...and nothing.
Then I tried plugging in the ol' SP-500 again. Within 15 seconds of hitting the power switch, I get the POST screen.
So I tried a little experiment...what if I connect the Ultra as quickly as possible while the motherboard is still "successfully juiced up?" It worked.
I'm not sure if I should RMA the motherboard...this thing it does where the voltages slowly come up has never really struck me as normal...or if I should RMA the PSU, or both?
Help me jonnyGURU, you're my only hope! </r2d2>
Edit: regardless of whether my motherboard is defective, it's really unacceptable for my 2-year-old craptastic power supply to boot my system on its first try and the universally praised brand new ultra does not...that's unacceptable. Why would that happen...
I unplugged the ol' sp-500 and got the new ultra situated in my case. It took about 30 minutes to get everything nice. I then tried to power up the machine, and it did the usual p5n32-e sli plus motherboard thing where when it's been powered off for a long time, the voltages come up slowly. I don't know if it's a defect or if it's designed that way, but basically none of the fans or magneto-optical drives are on right away, then the fans slowly spin up, then the magneto-optical drives come on. About 15 seconds after you hit the power switch, finally you get video output and the POST screen. Except this time, it never posted.
I tried a jumper CMOS clear, and nothing. I tried removing the battery and unplugging the PSU for 30 minutes...twice...and nothing.
Then I tried plugging in the ol' SP-500 again. Within 15 seconds of hitting the power switch, I get the POST screen.
So I tried a little experiment...what if I connect the Ultra as quickly as possible while the motherboard is still "successfully juiced up?" It worked.
I'm not sure if I should RMA the motherboard...this thing it does where the voltages slowly come up has never really struck me as normal...or if I should RMA the PSU, or both?
Help me jonnyGURU, you're my only hope! </r2d2>
Edit: regardless of whether my motherboard is defective, it's really unacceptable for my 2-year-old craptastic power supply to boot my system on its first try and the universally praised brand new ultra does not...that's unacceptable. Why would that happen...
Is that referring to my post as a whole, or why the SP-500 would work, or why the voltages slowly come up?
edit: well, your expertise in power supplies in combination with your lack of any input on this issue leads me to believe that it's most likely a motherboard problem, as I have always suspected. I'm going to try to get an RMA for my motherboard through asus. I don't know who much success I will have considering that I bought this as an open box item.
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I don't even know what you mean by "voltages slowly come up". Do you have a DMM plugged into a Molex and are reading 10V on the 12V and watch it "come up" to 12V? A slow post is a slow post, but that shouldn't have anything to do with how "voltages come up". Voltages are delivered to connectors in less than a second regardless of PSU or motherboard.
Yes, the voltages do actually "slowly come up," but only through the motherboard, not either PSU.
I had an issue with 2 of the 6 fan headers on my motherboard only delivering 8V when they are supposed to deliver 12V, and when I had the multimeter out I also confirmed that the voltages increase up to their final levels slowly.
Another thing my system does when it boots is send 5 pulses of sound of the speakers, 4 in rhythm followed by a 5th one after a slight delay. When I had the multimeter out I noticed that these pulses weren't just sound but also power fluctuations coming out the fan headers. I can record a sound clip of this, and I'll try to explain in the next paragraph...
I connected the leads of the multimeter to the fan header while the system was powered down. The multimeter reads .36V from all of the fan headers when the system is powered offThen I turned the system on while watching the multimeter, and saw some very strange things. Instantly, any fans connected directly to the PSU via molex begin to spin at full speed. The voltage on the multimeter dropped to zero when I turned the power on for about 1 second, and then in sync with the pulses it read .36V high, followed by 0V low. After the last pulse, it read 3.something volts, and then slowly increased to a final value of 8 or 12V, depending on the fan header. After the final voltage is reached, within a couple of seconds, I get a voltage dip that doesn't register correctly on the multimeter and the system begins to POST. I say it doesn't register correctly because I've never seen it dip to the same level twice. It never reads lower than 7, but it must go lower than that because any LEDs on any fans connected to a motherboard header all turn off...which they should stay lit at 7V.
I have not plugged the multimeter into any leads connected directly into the PSU; the fact that any fans connected directly to the PSU begin to spin at full speed immediately suggests that the voltage delivered by the PSU, both the antec and the ultra, is solid. It's just the motherboard that's weird.
This is how it behaves when doing a "warm" boot, meaning it's been shut down for any length of time but I never cut the power completely. I have never really studied the "cold" boot, but from my general observations I notice these things: the fans take much longer to spin up (ergo the climb from 3V to 12V goes much more slowly), and I don't hear any pulses.
This slow boot process is undocumented anywhere by asus.
So far, only the Antec can get my system to POST from a "cold" boot. There were a couple of isolated incidents in the past when it would not boot the system, but it only happened once or twice and it just resolved itself. The Ultra has so far never successfully got the system to POST from a "cold" boot, which I have tried about 5 times. It worked after I had the Antec hooked up, then hooked up the Ultra within about 2-3 minutes. Since then, I have not cut the power to the system completely.
Weird, huh?
edit2: nope, I lied, the Ultra pulses, too.
Edit: Actually, I don't get any pulses with the Ultra, but I still get the slow rise in voltage from the fan headers.
edit 3: so...my temps have gone way up with this PSU. My CPU is 2C hotter, and my NB is 10c hotter. I thought with the fan on the bottom of the PSU sucking air out of the case my temps would go down, but the exact opposite has happened. Although my temps have gone up...so has my max stable overclock. This PSU is an enigma!
edit 4: While I wouldn't call this PSU loud, it's definitely the loudest thing in my system. Even at idle, the fan emits a high pitched sound which I would describe as something in between a whine and a whistle. It's much more noticeable than the "whoosh" associated with my other fans: 2x 120mm antec sleeve, 1x 120mm yate loon sleeve, 1x 40mm silenx double ball, 1x 40mm scythe sleeve, 1x 80mm zalman double ball. The PSU is louder than all of those fans combined. The other fans are all quiet, almost silent except for the sound of the air moving. The PSU fan stands out above all of them. If this is typical I might return it. Oh...if I crank up the Zalman it is louder than the PSU but I never have to.
I had an issue with 2 of the 6 fan headers on my motherboard only delivering 8V when they are supposed to deliver 12V, and when I had the multimeter out I also confirmed that the voltages increase up to their final levels slowly.
Another thing my system does when it boots is send 5 pulses of sound of the speakers, 4 in rhythm followed by a 5th one after a slight delay. When I had the multimeter out I noticed that these pulses weren't just sound but also power fluctuations coming out the fan headers. I can record a sound clip of this, and I'll try to explain in the next paragraph...
I connected the leads of the multimeter to the fan header while the system was powered down. The multimeter reads .36V from all of the fan headers when the system is powered offThen I turned the system on while watching the multimeter, and saw some very strange things. Instantly, any fans connected directly to the PSU via molex begin to spin at full speed. The voltage on the multimeter dropped to zero when I turned the power on for about 1 second, and then in sync with the pulses it read .36V high, followed by 0V low. After the last pulse, it read 3.something volts, and then slowly increased to a final value of 8 or 12V, depending on the fan header. After the final voltage is reached, within a couple of seconds, I get a voltage dip that doesn't register correctly on the multimeter and the system begins to POST. I say it doesn't register correctly because I've never seen it dip to the same level twice. It never reads lower than 7, but it must go lower than that because any LEDs on any fans connected to a motherboard header all turn off...which they should stay lit at 7V.
I have not plugged the multimeter into any leads connected directly into the PSU; the fact that any fans connected directly to the PSU begin to spin at full speed immediately suggests that the voltage delivered by the PSU, both the antec and the ultra, is solid. It's just the motherboard that's weird.
This is how it behaves when doing a "warm" boot, meaning it's been shut down for any length of time but I never cut the power completely. I have never really studied the "cold" boot, but from my general observations I notice these things: the fans take much longer to spin up (ergo the climb from 3V to 12V goes much more slowly), and I don't hear any pulses.
This slow boot process is undocumented anywhere by asus.
So far, only the Antec can get my system to POST from a "cold" boot. There were a couple of isolated incidents in the past when it would not boot the system, but it only happened once or twice and it just resolved itself. The Ultra has so far never successfully got the system to POST from a "cold" boot, which I have tried about 5 times. It worked after I had the Antec hooked up, then hooked up the Ultra within about 2-3 minutes. Since then, I have not cut the power to the system completely.
Weird, huh?
edit2: nope, I lied, the Ultra pulses, too.
Edit: Actually, I don't get any pulses with the Ultra, but I still get the slow rise in voltage from the fan headers.
edit 3: so...my temps have gone way up with this PSU. My CPU is 2C hotter, and my NB is 10c hotter. I thought with the fan on the bottom of the PSU sucking air out of the case my temps would go down, but the exact opposite has happened. Although my temps have gone up...so has my max stable overclock. This PSU is an enigma!
edit 4: While I wouldn't call this PSU loud, it's definitely the loudest thing in my system. Even at idle, the fan emits a high pitched sound which I would describe as something in between a whine and a whistle. It's much more noticeable than the "whoosh" associated with my other fans: 2x 120mm antec sleeve, 1x 120mm yate loon sleeve, 1x 40mm silenx double ball, 1x 40mm scythe sleeve, 1x 80mm zalman double ball. The PSU is louder than all of those fans combined. The other fans are all quiet, almost silent except for the sound of the air moving. The PSU fan stands out above all of them. If this is typical I might return it. Oh...if I crank up the Zalman it is louder than the PSU but I never have to.
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