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A8N-SLI Deluxe: many defective boards identified
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I have a quick generic repsonse to the dual rail idea.
I own 3 PSU's at the moment a PC Power and Cooling 510W EPS12V, a ThermalTake 480w, and a Zippy 400w.
Which PSU do you think works the best on my machine? Interestingly enough it is the Zippy (30amps on the 12v rail)
My PC Power and Cooling I couldn't get to work stable with the a8n-sli (even w/only one HD and one 6800GT)... Side note is that it is EPS12v which means it has two 12v rails. It works great on my older p4 865pe system even with many disks attached.
The thermaltake 480w I BS cause the 12v is only 18amps so it is barely able to hold (although it worked alot better than the PC Power and Cooling)
I have not had a single crash with my zippy 400w as of yet. Well yeah i have but that's cause I was trying to run at 2.7ghz or trying to run my memory at 2-3-2-9 @ 240mhz so I knew the reason, but all my inital problems are gone.
I own 3 PSU's at the moment a PC Power and Cooling 510W EPS12V, a ThermalTake 480w, and a Zippy 400w.
Which PSU do you think works the best on my machine? Interestingly enough it is the Zippy (30amps on the 12v rail)
My PC Power and Cooling I couldn't get to work stable with the a8n-sli (even w/only one HD and one 6800GT)... Side note is that it is EPS12v which means it has two 12v rails. It works great on my older p4 865pe system even with many disks attached.
The thermaltake 480w I BS cause the 12v is only 18amps so it is barely able to hold (although it worked alot better than the PC Power and Cooling)
I have not had a single crash with my zippy 400w as of yet. Well yeah i have but that's cause I was trying to run at 2.7ghz or trying to run my memory at 2-3-2-9 @ 240mhz so I knew the reason, but all my inital problems are gone.
Plus, like I said, I saw you are significantly overclocked and the ASUS manual probably does not make those power recommendations based on overclocked systems. I got tired of all the dilemma and went ahead and ordered this guy from Monarch:
http://www.monarchcomputer.com...6&Category_Code=ps-400
It's ATX2 and I think it has the 24 pin connector. Its looks to be single rail 450 Watt with 26 Amp on the +12V. It's OCZ so the quality should be fine. It's under $100 and free 5-7day shipping plus no tax ordered on the interweb 🙂
I will start out running 2x PCI express 6600GT and a Winchester 3200+. Only 1 SATA HD, 1 IDE optical drive, and 1 Gig (2x512 dual channel) PC 3200. This should more than handle that load or even 2 6800GT's with whatever Winchester core CPU I want to throw at it (I think the highest one now is the 3500+ @ 2.2 GHz?) If it doesn't, then I'll be looking to ASUS for answers.
ok, ive read through this thread and ive got a few questions. i understand that the newer 24 supplies have 2 seperate 12v rails now, each supplying seperate amperage. i see a few posts on how the 2 rail psu's are not any good for the sli boards, because of the sli configurations drawing up to 25+ amps, and the average 2 rail psu supplies ~18 amps per rail. ok, how physically are the rails split up? i would imagine one rail supplies the normal 20 pin, and the extra rail supplies the extra 4 pins that comes with the new atx standard, right? does anyone know how the rails are split up on the motherboard, as far as what rail is powering what? what does the extra 4 pins supply power to? you would think that the board would be designed to split up the amperage coming from seperate rails so there would not be any problems, example; one rail @ 18 amps supplys power to mobo, cpu etc, and the other 18 amp rail dedicated to the video cards, just for an example.
BigGreenMat
Member
So basically having a NeoPower I am screwed? $110 for nothing? I mean I have been having BSODs, but I figured they were from having troubles with OS installs or possibly a bad HDD, not my powersupply considering I spent a considerable amount of time considering supplies and went with one I was sure wouldn't miss for this set up (only other I thought would have been PCP&C 510 which is well over $200 or high end OCZ which is around $200) and now it is supposed to be the cause of my problems? That is whack.
Went through and double checked what comes from rail 1 and 2. The 24 pin connector, pci-e connector, peripheral/floppy connector, and SATA connector all draw from Rail 1 on a NEOPower. The extra 12v Mobo Power connector is what draws from rail 2. So that is the breakdown.
Went through and double checked what comes from rail 1 and 2. The 24 pin connector, pci-e connector, peripheral/floppy connector, and SATA connector all draw from Rail 1 on a NEOPower. The extra 12v Mobo Power connector is what draws from rail 2. So that is the breakdown.
so, the motherboard is supplied by a single rail that on avarge, has a supply of ~18amps, and everything else is supplied by the other rail including the cpu? i am really questioning this. why would this be designed so inefficiently? what application would you need that much amperage to supply to a motherboard? even if it is designed this way, wouldnt the pci-e video cards be drawing power from both the motherboard, and the seperate power plugs, in return, they would be drawing from both rails? i am very interested to know how the power is split up on these boards and psu's.
imported_Ainaas
Junior Member
Before I shut down my old system I changed my IDE controller to the windows standard generic driver, so I was able to pull the old drives and directly transfer them, boot into safe mode on XP, and update the drivers. Once during updating I had the system do the old video blank on me. I shut it down and let it sit for a few hours, on the reboot I was able to get everything done. I also forgot to mention that the system made it through a Source Stress Test (the CS:S one) and got a good framerate with no visible glitches on the test. The system was up for maybe 5 minutes after closing CS:S, and then I believe the video went blank again - so i'm fairly sure it's not the video card (again) because the overheating should have been closer to the heavy usage it got during the stress test.
But I got all the drivers set up okay, except for the RAID driver and I never installed NV IDE (it wasn't detected since I still had the generic IDE driver setup). Since the system was so unstable though I put all the drives back in my old machine (kudos to XP for automatically recognizing the hardware profile - with all the drivers for both machines there I can freely boot XP on either machine and it will have all the connected hardware there in the Device Manager with no Phantom Devices). The remainder of my testing was with the above mentioned Optical Drive and bootable diagnostic CD.
Edit for grammar.
But I got all the drivers set up okay, except for the RAID driver and I never installed NV IDE (it wasn't detected since I still had the generic IDE driver setup). Since the system was so unstable though I put all the drives back in my old machine (kudos to XP for automatically recognizing the hardware profile - with all the drivers for both machines there I can freely boot XP on either machine and it will have all the connected hardware there in the Device Manager with no Phantom Devices). The remainder of my testing was with the above mentioned Optical Drive and bootable diagnostic CD.
Edit for grammar.
flexy wrote up a rather nice explanation of it on this thread here:
http://forums.anandtech.com/me...id=27&threadid=1478987
What I got from reading that post was that, even with a 20 pin PSU, the high end graphics cards usually have power connectors on them to which you can connect a 6 pin power source directly from your PSU if it has one, or you can buy an adapter to turn 2 four-pin connectors into one 6 pin to power the graphics card so it doesn't need to draw power from the motherboard PCI express slot which can't really supply enough power anyway due to the power ratings of the wires. If you have a 24-pin connector, the extra 4 pins are solely to provide extra power to the pci express cards and you shouldn't need to hook up the power connector on the video card. However, if the power demands for 2 cards in SLI configuration are say 18A and you have a dual rail PSU that has a 15A and a 16A, one rail probably has more power than it needs while neither has enough to juice the video cards. One rail with 26A would do the trick since the motherboard can draw only what it needs and the video cards can draw on whats left over. . .make sense or am I totally off on a tangent on this? Somebody who knows more about this stuff please correct me if I'm all whacked up on goofball.
http://forums.anandtech.com/me...id=27&threadid=1478987
What I got from reading that post was that, even with a 20 pin PSU, the high end graphics cards usually have power connectors on them to which you can connect a 6 pin power source directly from your PSU if it has one, or you can buy an adapter to turn 2 four-pin connectors into one 6 pin to power the graphics card so it doesn't need to draw power from the motherboard PCI express slot which can't really supply enough power anyway due to the power ratings of the wires. If you have a 24-pin connector, the extra 4 pins are solely to provide extra power to the pci express cards and you shouldn't need to hook up the power connector on the video card. However, if the power demands for 2 cards in SLI configuration are say 18A and you have a dual rail PSU that has a 15A and a 16A, one rail probably has more power than it needs while neither has enough to juice the video cards. One rail with 26A would do the trick since the motherboard can draw only what it needs and the video cards can draw on whats left over. . .make sense or am I totally off on a tangent on this? Somebody who knows more about this stuff please correct me if I'm all whacked up on goofball.
Here are a couple threads which are more on topic for what this thread has turned into. This thread has kinda taken a tangent from its original topic
http://forums.anandtech.com/me...id=29&threadid=1477892
http://forums.anandtech.com/me...id=29&threadid=1478819
http://forums.anandtech.com/me...id=29&threadid=1477892
http://forums.anandtech.com/me...id=29&threadid=1478819
ok, very good article flexy. explains some things. flexy, did you find actual documentation on what componetns are being powered by the seperate 12v rails? i think you are right when you say the extra 4 pin connector is made for the pci-e slots, and i would imagine the other 20 pins have stayed the same, just like previous motherboard power layouts. i am thinking the reason asus put the ez plug molex connector by the pci-e slots is for people that dont have the 24 pin psu, just an idea. also, does anyone know the approx amounts that a video card draws off of the 12v rail? i see a lot of people figuring out power requirements by assuming all of the ~100 watts that a video card draws is coming from the 12v line. dont most video cards also draw from the 3.3 and 5v rails? if i remember correctly my 9800 pro drew quite a bit of power of the 5 and 3.3v rails, rather than the 12v.
ok, the way i understand it then, one rail off a decent quality dual 12v rail psu should be more than enough to power 2 high end video cards, while leaving the second rail for the rest of the system, eg; cpu, mobo, hdd's, etc. i cant see why you would NOT want to purchase a new 24pin dual rail psu, if you are planning on running this board, and are also in the market for a new psu. sure it will work fine with a 20 pin, but why update to another 20 pin, when the standards seem to be changing over to 24? asus must have put the 24 pin plug in for a reason, and im sure they designed the board to work with todays 24 pin psu's.
GuitarDaddy
Lifer
24pin PS's are not all dual rail PS's. There are plenty of single rail 24pin PS's.
If you want to continue to beleive a dual rail PS will work well with this board, go right ahead.
It defies logic, and ignores the fact that seemingly everyone trying to run 2 high end cards and a dual rail power supplies is having constant problems, and everyone who is successfully running SLI with highend cards is using a high quality single rail PS.
People are still posting "If you plug a connector from the 20a rail, and a connector from the 18a rail into the same device(mobo), that the device is getting 38a. WRONG, WRONG, WRONG!!! I guess you guys also think if you plug into two 110 wall outlets you've got 220!(try running your dryer this way) You can connect (20) 20a power supplies together and you still have 20a!!!!
Wattage is cumulative and can be added together in this manner, ampherage/voltage is not! A good analogy is water through a hose(s). Wattage is like volume, Ampherage is like water pressure, If you add a second hose you are certainly increasing the volume but you are not increasing the pressure.
If you want to continue to beleive a dual rail PS will work well with this board, go right ahead.
It defies logic, and ignores the fact that seemingly everyone trying to run 2 high end cards and a dual rail power supplies is having constant problems, and everyone who is successfully running SLI with highend cards is using a high quality single rail PS.
People are still posting "If you plug a connector from the 20a rail, and a connector from the 18a rail into the same device(mobo), that the device is getting 38a. WRONG, WRONG, WRONG!!! I guess you guys also think if you plug into two 110 wall outlets you've got 220!(try running your dryer this way) You can connect (20) 20a power supplies together and you still have 20a!!!!
Wattage is cumulative and can be added together in this manner, ampherage/voltage is not! A good analogy is water through a hose(s). Wattage is like volume, Ampherage is like water pressure, If you add a second hose you are certainly increasing the volume but you are not increasing the pressure.
I, for one, am not saying it works better with a dual rail PSU. It theoretically should work with either single or dual depending on what you put in the machine. But you gotta figure out for yourself what the power requirements are. If you figure out that you need to have say 16A on one rail and only need say 8A on the other rail, but your PSU has 2 x 15A +12V rails, you have a total of 30A but then one rail has 7A more than you need and the other is insufficient by 1A. Your total need is only 24A. Wouldn't it be nice if you could steer some of that extra 7A over to the other rail? Well, I think I have seen some higher priced 2 rail PSU's that will let you do that. Now if you have a single rail that has 26A, then as I see it, whatever components can draw whatever power they need off of the 1 rail and only 2A go to waste. With the dual rail system you are wasting 7A and still not accomplishing your power needs. This might not happen in every case though. . .it depends on each persons individual system power needs. It just makes a difference because you are dipping from 2 smaller pools in one case and 1 large pool in the other.
ahurt, i was thinking the same thing. it would be nice to know exactly how much is needed on each rail, its much easier to figure out how much 12v current you need, but when you split things up into two rails, each with different power requirements, things are getting trickier.
guitardaddy, i dont understand your reasoning at all, sorry. i dont see how having 2 seperate rails each with their own amperage ratings defies logic. also, theres more than enough people running dual rail power supplies with no problems.
why cant you tally up the total current of the two rails? granted the total amperage between the two is not being shared by all components, so some components might if fact starve for current on a certain rail. dual rail is pretty much the same as a single rail, with the amperage divided across two rails instead of it all being one one. you are comparing 110volt wall outlets which are two completely different things. i think you are confusing voltage with amperage here. correct me if im wrong,
guitardaddy, i dont understand your reasoning at all, sorry. i dont see how having 2 seperate rails each with their own amperage ratings defies logic. also, theres more than enough people running dual rail power supplies with no problems.
why cant you tally up the total current of the two rails? granted the total amperage between the two is not being shared by all components, so some components might if fact starve for current on a certain rail. dual rail is pretty much the same as a single rail, with the amperage divided across two rails instead of it all being one one. you are comparing 110volt wall outlets which are two completely different things. i think you are confusing voltage with amperage here. correct me if im wrong,
This is wrong. Voltage is not additive, current is. One of the definitions of the watt is voltage times current. Since the voltage is constant, current must increase for power (watts) to increase. Amperage is essentially the flow rate and 1 amp is by definition 6.28 billion billion electrons per second.
My new SLI power supply! These are gimmicks to sell the damn psu's. These wern't made for SLI boards, someone in marketing figured out a way to sell $hit loads of psu's by marketing these dual rail psu's as "Special" and "For SLI." They aren't. You can buy PCI-E molex to PCI-E adapters that fit on any molex, to draw power from a substantial 12v source.
With dual rail, you are hoping that a single rail isn't maxed out when using one rail for the board and one rail for the graphic cards. You are thinking that the cards and the board will have seperate 12v rails, but this isn't the case. The cards will still draw power from the board even with the use of the PCI-E power connectors attached directly to the cards. So with dual rail, you are supplying an 18a (optimistic source) to the board which will feed the processor, all onboard components, and the PCI-E slots, and the second rail is used for what---the drives, fans that aren't powered by the motherboard, and some current to the graphic cards. You are still taxing the rail that is powering the motherboard.
Now, if they made try SLI psu's, with dual 24a on the 12v rails, it would be a different story---but that animal doesn't currently exist.
With dual rail, you are hoping that a single rail isn't maxed out when using one rail for the board and one rail for the graphic cards. You are thinking that the cards and the board will have seperate 12v rails, but this isn't the case. The cards will still draw power from the board even with the use of the PCI-E power connectors attached directly to the cards. So with dual rail, you are supplying an 18a (optimistic source) to the board which will feed the processor, all onboard components, and the PCI-E slots, and the second rail is used for what---the drives, fans that aren't powered by the motherboard, and some current to the graphic cards. You are still taxing the rail that is powering the motherboard.
Now, if they made try SLI psu's, with dual 24a on the 12v rails, it would be a different story---but that animal doesn't currently exist.
GuitarDaddy
Lifer
Read more carefully, my point exactly is Voltage is not additive. And yes current x volts = watts, and current is additive therefore wattage is additive. And yes Amperage is the flow rate which again demonstrates the point, putting two sources together with the same flow rate doesn't double the flow rate.
GuitarDaddy
Lifer
I didn't say having two power rails defies logic, trying to add the amps together from two seperate rails defies logic, AMP's are not additive.
why cant you tally up the total current of the two rails? granted the total amperage between the two is not being shared by all components, so some components might if fact starve for current on a certain rail. dual rail is pretty much the same as a single rail, with the amperage divided across two rails instead of it all being one one. you are comparing 110volt wall outlets which are two completely different things. i think you are confusing voltage with amperage here. correct me if im wrong,[/quote]
My comparison to the wall outlets perhaps is not the best analogy. But the fact remains you can't add amps together in this manner.
And point me to someone who is running 2 x 6800U sucessfully with a dual rail PS.
I have to say I tend to agree with GuitarDaddy but that's not to say that I don't think a dual rail PSU would not work on a system without high power demand. But I think a good strong single rail PSU should work in all cases and is therefore the simpler choice. Plus, the specs in the owners manual (posted somewhere up above) really look more like they are more characteristic of a single rail PSU than a dual rail. I ordered the OCZ 450Watt ModStream (+12V 26A) today and I think that should be good for my sytem unless I decide to put dual 6800 Ultra cards and an Athlon 64 FX. . .which guess what. . .it aint happening.
My system will look like this, hope it works:
Asus A8N SLI Deluxe
Athlon 64 3200+ (2.0GHz) Winchester (90nm Socket 939)
1 Gig (2x512 dual channel) Corsair PC3200
2 x BFG 6600 GT OC, PCI Express 128MB
Maxtor 250 GB SATA 7200 RPM w/ 16MB Cache
OCZ ModStream 450Watt PSU
Sony DVD/CD-RW combo drive - IDE
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