Do You Think a 365w PSU is sufficient for a Radeon 6850?

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Madmick

Member
Apr 7, 2012
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Okay, you guys have been awesome (particularly BlastingCap and DMA), but I was hoping for consensus, so I Googled the HP Part No. # to give you guys absolute clarity. Here is my PSU (and it is, in fact, manufactured by Delta):
http://www.alibaba.com/product-tp/105874226/HP_Power_Supplies_Part_Number_460968.html

I wasn't able to find a page on this unit anywhere specifying whether or not it had the PCI-E 6-Pin cable. The exact same HP Part# pulled results for two other identical, but more powerful models- a 530w and 650w- and their pages did specify that they comes with a PCI-E 6 cable.

So I wanted to revisit this question for certainty:

pcie6.jpg


The image on the left is of the connector; the image on the right is of the molex adapters. Does this connector connect to the motherboard or the PSU? I assumed it connected to the motherboard since it appears to be plastic, and I figured anything that hooks into the PSU will be metal (I can't see inside my PSU because it's encased in metal and bolted together; I'd have to unbolt and remove the motherboard and fan in order to open it up, and I'd prefer not doing that).

In that image, the molex adapters I see appear to be male, and each have 4 pins. Earlier, I mentioned that I saw a white casing like these labeled "P6" with wires feeding into it protruding from the PSU. It also has 4 pins, but they are female, and since it's hanging out of the PSU, I'm guessing that this end attaches to the motherboard.

Therefore, assuming that the PCI-E 6-pin connector from the image above (on the left) connects directly into the PSU, then perhaps I was mistaken, and my PSU does have it, and this "P6" casing is the other end?
 
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TemjinGold

Diamond Member
Dec 16, 2006
3,050
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Assuming both images are of the same part, the connector on the left goes into a graphics card. The thing on the right basically allows you to adapt 2 molexes to one 6-pin graphics power plug. If your PSU doesn't have a 6-pin native and you can only get it through this adaptor, it may not be wise to use such a PSU for a graphics card that needs it...
 

blastingcap

Diamond Member
Sep 16, 2010
6,654
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Delta is a legitimate maker of mediocre power supplies. They aren't great but they aren't that bad and are definitely not of the "explode if you sneeze at it" variety.

6-pin PCIe = almost always used for video cards. The 6850 needs one six-pin PCIe connector like the one you show on the left. 6-pin PCIe can power up to 75W. The 6850 gets the rest of its power from the PCI-Express slot itself.

4-pin MOLEX = ancient PC power cable variety; it's there for legacy compatibility reasons. Older hard drives, optical drives, fans, etc. use 4-pin MOLEX natively. 4-pin MOLEX can power up to 60W. (Source: http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral )

Facts:

4-pin MOLEX = 60W max.
x2 4-pin MOLEX = 120W max.
6-pin PCIe = 75W max.

Therefore:

2 4-pin MOLEX -> 6-pin PCIe is safe.
1 4-pin MOLEX -> 6-pin PCIe is not safe.

Narrowing down 120W of power throughput to 75W is just fine. But obviously, using a 60W cable when the card is expecting 75W is not okay.

One of my recent video cards came with such an adapter, too. If you don't have the PSU to physically examine right now (what you're writing is unclear as to whether or not you already have the old PC or are waiting to pick it up), and you don't have the 2 4-pin MOLEX -> 6-pin PCIe connector already, then maybe you should hold off on buying the 6850 until you know for sure if you need an adapter. If the PSU has a 6-pin PCIe connector, then you're all set. If it doesn't, then maybe try to buy a 6850 that comes with the adapter in the box to save a little money. Newegg has photos of what comes inside the box, so that's an easy way to browse.

Edit to add: this page shows you what all the common PSU connectors look like: http://www.playtool.com/pages/psuconnectors/connectors.html Pay special attention to the 4-pin MOLEX peripherals paragraph: "Current power supplies usually have at least two separate peripheral power cables, each of which has two or more peripheral connectors. When you're plugging in multiple high powered devices it's a good idea to spread the load between all of your cables. Don't just plug all your devices into one cable unless they're relatively low load devices. Spreading the current between the cables reduces the voltage drops and power loss. If they're relatively low current devices like fans or it's just a disk drive or two then it doesn't really matter. But if you're putting lots of hard disks into a computer (some can draw almost 3 amps at 12 volts when doing some operations) or connecting a video card's auxiliary power, then spread the loads between the peripheral power cables. It's also helpful if you use a connector as close to the PSU as possible rather than sticking things at the end of the cable. Extra wire just means more voltage drop. And if you're using a peripheral connector to PCI Express adapter then be sure to plug each of the adapter's peripheral connectors into a separate PSU cable. They gave you two peripheral connectors for a reason. Plugging them both into the same PSU cable forces your video card to draw its 12 volt power through one 18 gauge wire. That increases your voltage drop and power dissipation in the cable." -- http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral


Okay, you guys have been awesome (particularly BlastingCap and DMA), but I was hoping for consensus, so I Googled the HP Part No. # to give you guys absolute clarity. Here is my PSU (and it is, in fact, manufactured by Delta):
http://www.alibaba.com/product-tp/105874226/HP_Power_Supplies_Part_Number_460968.html

I wasn't able to find a page on this unit anywhere specifying whether or not it had the PCI-E 6-Pin cable. The exact same HP Part# pulled results for two other identical, but more powerful models- a 530w and 650w- and their pages did specify that they comes with a PCI-E 6 cable.

So I wanted to revisit this question for certainty:

pcie6.jpg


The image on the left is of the connector; the image on the right is of the molex adapters. Does this connector connect to the motherboard or the PSU? I assumed it connected to the motherboard since it appears to be plastic, and I figured anything that hooks into the PSU will be metal (I can't see inside my PSU because it's encased in metal and bolted together; I'd have to unbolt and remove the motherboard and fan in order to open it up, and I'd prefer not doing that).

In that image, the molex adapters I see appear to be male, and each have 4 pins. Earlier, I mentioned that I saw a white casing like these labeled "P6" with wires feeding into it protruding from the PSU. It also has 4 pins, but they are female, and since it's hanging out of the PSU, I'm guessing that this end attaches to the motherboard.

Therefore, assuming that the PCI-E 6-pin connector from the image above (on the left) connects directly into the PSU, then perhaps I was mistaken, and my PSU does have it, and this "P6" casing is the other end?
 
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Madmick

Member
Apr 7, 2012
144
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76
Edit to add: this page shows you what all the common PSU connectors look like: http://www.playtool.com/pages/psuconnectors/connectors.html Pay special attention to the 4-pin MOLEX peripherals paragraph: "Current power supplies usually have at least two separate peripheral power cables, each of which has two or more peripheral connectors. When you're plugging in multiple high powered devices it's a good idea to spread the load between all of your cables. Don't just plug all your devices into one cable unless they're relatively low load devices. Spreading the current between the cables reduces the voltage drops and power loss. If they're relatively low current devices like fans or it's just a disk drive or two then it doesn't really matter. But if you're putting lots of hard disks into a computer (some can draw almost 3 amps at 12 volts when doing some operations) or connecting a video card's auxiliary power, then spread the loads between the peripheral power cables. It's also helpful if you use a connector as close to the PSU as possible rather than sticking things at the end of the cable. Extra wire just means more voltage drop. And if you're using a peripheral connector to PCI Express adapter then be sure to plug each of the adapter's peripheral connectors into a separate PSU cable. They gave you two peripheral connectors for a reason. Plugging them both into the same PSU cable forces your video card to draw its 12 volt power through one 18 gauge wire. That increases your voltage drop and power dissipation in the cable." -- http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral
Yeah, that was the page I was looking at earlier. I have the PC with me; I'm able to look inside it.

There's a "4 Pin ATX + 12V Power Cable" plugged in to the motherboard. That was the one I described to dma earlier, but he said there were no 4-Pin PCI-E cables: only 6-pin. That confused me because in the table listed below those images the "4 Pin 12 volt cable" is included in the "PCI Express 2.0" box: the most recent cable technology introduced in 2007.
That white encasing labeled "P6" that isn't plugged in that I've been talking about is a "4 Pin Peripheral Power Cable", and is also included in that box in the table chart.

That page says the maximum current on the 4-Pin 12V Cable is 16 Amps (192 Watts). His conservative estimate for maximum actual current on the 4-Pin Molex Cable is 5 Amps (60 watts). That's a combined total of 21 Amps. That barely clears the 20 Amp minimum and doesn't meet the 24.2 Amp recommended current by that PSU calculator.

So dma's very first post in this thread turned out to be right on the money. This PSU setup could handle a 6670, but I'd probably have to buy a new PSU to support a 6850.


Oh Mylanta! Decisions, decisions.
 

dma0991

Platinum Member
Mar 17, 2011
2,723
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I'm confident there are no 4 pin PCIE cables and there are no GPUs that would take a 4 pin, most are 6,6+8 or 8+8 and in the case of the HD6850, 6 pin PCIE. What you're looking at is either the extra 4 pin that most 24 pin cables are except it might come in a 20+4 fashion. It is also likely that it is a EPS cable(as you call it, 4 Pin 12 volt cable) that is meant to be plugged on to the motherboard near the CPU socket and it will sometimes be in a 4 or 4+4.

Even if you tried to force a 4 pin EPS into your PCIE slot of your GPU, it won't fit as the ends of the connectors are keyed differently to prevent users from accidentally plugging it into the wrong port. Also to note if you do decide to use the original PSU instead, you will need 2 molex ports and I mention this as some OEM PSUs are stripped down to what is necessary and some would only have 1.
 

birthdaymonkey

Golden Member
Oct 4, 2010
1,176
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81
Everyone seems to be overlooking another solution: The 7750, a much more capable card than the 6670, does not require an external power connecter. They currently go for $110 and should get 75-80% of the performance of a 6850.
 

blastingcap

Diamond Member
Sep 16, 2010
6,654
5
76
Everyone seems to be overlooking another solution: The 7750, a much more capable card than the 6670, does not require an external power connecter. They currently go for $110 and should get 75-80% of the performance of a 6850.

Not overlooking it, it's just that it sucks for price/performance.

A 4-in plug that looks sort of like two-thirds of a 6-pin PCIe connector is probably meant for the CPU fan. Look for where it goes somewhere near the CPU.

You don't need a new PSU. I think that part has been settled. Worse case scenario you can get a dual 4-pin MOLEX -> 6-pin PCIe connector like in your photo.

A slightly more expensive option is getting something like the Corsair 430W PSU and calling it a day.
 

Madmick

Member
Apr 7, 2012
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Whoa. Getting more confused. Okay, I snapped an image of the PC interior with my tablet. I can't seem to embed it, so I just made it public on my Flickr:
http://www.flickr.com/photos/70978589@N05/6913829388/
If you want to see any vector or component in more detail, just specify, and I'll take more photos.
A 4-in plug that looks sort of like two-thirds of a 6-pin PCIe connector is probably meant for the CPU fan. Look for where it goes somewhere near the CPU.
I presume you're talking about the one he calls a "4 Pin Peripheral Power Cable" and which he notes is commonly called a "4 Pin Molex Cable":
peripheralpic.jpg


Now that you mention it, I can't find anywhere on the motherboard to plug this in. I checked everything including near the CPU and its fan, and I can't find a port with 4 steel teeth like in the above photo anywhere. I know my Flickr photo only shows the face of the motherboard, but you can double check (it's the big white casing in the middle, slightly upper-right). There's only a DVD-player, no CD-ROM, maybe it was meant to connect to that? That appears to be an HDD in the image above. The cables are very short. They can't reach the bottom of the motherboard. Where you see them in my Flickr photo is the extent of their range- at least as they are. So it would need some kind of extension to reach where my hard drives are stored at the bottom left.

I'm a bit concerned about this because I need those 5 Amps if I don't upgrade this PSU, and I would really prefer not upgrading.
I'm confident there are no 4 pin PCIE cables and there are no GPUs that would take a 4 pin, most are 6,6+8 or 8+8 and in the case of the HD6850, 6 pin PCIE. What you're looking at is either the extra 4 pin that most 24 pin cables are except it might come in a 20+4 fashion. It is also likely that it is a EPS cable(as you call it, 4 Pin 12 volt cable) that is meant to be plugged on to the motherboard near the CPU socket and it will sometimes be in a 4 or 4+4.

Even if you tried to force a 4 pin EPS into your PCIE slot of your GPU, it won't fit as the ends of the connectors are keyed differently to prevent users from accidentally plugging it into the wrong port. Also to note if you do decide to use the original PSU instead, you will need 2 molex ports and I mention this as some OEM PSUs are stripped down to what is necessary and some would only have 1.
I'm just going by the rubric in the table on the referenced page:
http://www.playtool.com/pages/psuconnectors/connectors.html
Even though these are included in the "PCI Express 2.0" box, the only listed cables in that class that actually include the term "PCI Express" in their title are the 6 pin and 8 pin. I think this is just semantics at this point. I understand that I'm going to need a 6-pin or 8-pin adapter depending on the card I choose since I don't see one anywhere in my PC and these video cards require them.
You don't need a new PSU. I think that part has been settled. Worse case scenario you can get a dual 4-pin MOLEX -> 6-pin PCIe connector like in your photo. A slightly more expensive option is getting something like the Corsair 430W PSU and calling it a day.
You still don't think I need a new PSU for the 6850 to be safe? Even requiring molex adapters?
Everyone seems to be overlooking another solution: The 7750, a much more capable card than the 6670, does not require an external power connecter. They currently go for $110 and should get 75-80% of the performance of a 6850.
Actually, not a bad thought since I'm still uncertain if my PSU can safely power the 6850. If not, despite the 7750's lack of value, it's cheaper than a new PSU + 6850, especially out of pocket. And there's always the chance it drops to $105 plus a $20 rebate or something, so I appreciate the mention.

Since BlastingCap mentioned VRAM as the primary attribute determining gaming performance (on the same CPU), I also noticed a cheap 6750 2GB on J&R. I present these as my video card options:

Asus Radeon 6850 (NewEgg: $130 after $20 rebate)
Max= 127 Watts
http://www.newegg.com/Product/Produc...82E16814121419

XFX Radeon 6750 2GB (J&R: $82)
Max= 86 Watts
http://www.jr.com/xfx/pe/XFX_HD657XC...ductTabDetails

Sapphire Radeon 6670 1GB (Amazon: $55 after $15 rebate)
Max= 63 Watts
http://www.amazon.com/Sapphire-Radeo.../dp/B005HH35KS

Sapphire Radeon 7750 (Amazon: $110)
Max= 55 Watts
http://www.amazon.com/Sapphire-11202...3961871&sr=8-2


Note: Looks like the XFX 6850 that was $120 after the rebate cleared stock. I've been watching, and I've noticed NewEgg typically runs its best rebate specials the first 1-2 weeks of the month.
 
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dma0991

Platinum Member
Mar 17, 2011
2,723
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I'm just going by the rubric in the table on the referenced page:
http://www.playtool.com/pages/psuconnectors/connectors.html
You will need a 6 pin PCIE which will eventually terminate at this. The problem is that you do not have anything that resembles a 6 pin PCIE, the only way to solve that is for your PSU to have 2 molex connectors which is a part of a molex to 6 pin PCIE adapter, some GPUs that you buy provides them. Since I could only locate 1 molex in the picture, your chances are slim unless you could find a single molex to PCIE 6 pin adapter which is rare and don't come in the box with most GPUs. Unless you could locate another molex connector from your PSU(to attach it to the molex to 6 pin PCIE adapter), your only choice would be to eventually get a CX430.

Since BlastingCap mentioned VRAM as the primary attribute determining gaming performance (on the same CPU), I also noticed a cheap 6750 2GB on J&R. I present these as my video card options:
More VRAM does not necessarily imply that the GPU performs better.
 

blastingcap

Diamond Member
Sep 16, 2010
6,654
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No; I mean a square-shaped thing that literally looks like two-thirds of a six-pin PCIe connector. That is probably a CPU fan connector or something. All of this should be preinstalled properly on the computer anyway.

4-pin MOLEX does not plug directly into motherboard. Typically it is used for legacy CD-ROM/DVD-ROM drives and hard drives, possibly also case fans and such.

If your PSU has an available 6-pin PCIe slot, get a 6850, plug it in, and install the 6850.

If your PSU has two available MOLEX 4-pin connectors and you have a (x2) MOLEX -> 6-pin PCIe adapter, or the card you want includes an adapter, use the adapter and install the 6850.

If your PSU has no 6-pin PCIe and no dual-MOLEX and you have no adapter, either:

a) get the Corsair 430W which has a 6-pin PCIe connector for sure and install it and get almost any card you want and you will be fine.

or

b) get a card that requires no external connectors, such as a 7750 or 6670. It really depends on your gaming resolution. 6670 is fine for 1680x1050, but probably a little too weak for 1080p.

Performance-wise, a 5770, 6770, and 7750 are basically tied.

A 7750 not a bad card, just priced too high compared to its peer cards. It should be a $99 card at most. This is because if you wait for a sale and don't mind rebates, you can get a 6850 or a GTX 460 (1GB) for less than $120. A 6850 is ~40% faster than the 7750. Or buy a new or used 5770 or 6770 for less than $80 and get equal performance to the overpriced 7750. (But note that the 5770/6770 requires an 6-pin PCIe connector. By the way, the 67xx cards are just rebadged 57xx cards with maybe a slight difference in ports and minor non-performance related improvements that don't really change anything. They are essentially the same cards with different series numbers.)

A 7750/6770/5770 is decent performance for 1080p (I am assuming you will game at 1080p). Frankly it's enough to play any game out there although you will need to lower setting to Medium for the heaviest hitters like Crysis, BF3, Metro 2033, etc. But 99% of games will run at high, and maybe even with some anti-aliasing enabled. All three are easy to overclock and if your case is even remotely decent at cooling your video card you should have at LEAST a 15% overclock. Many people get more, with good cooling in place, but your free old computer probably has a crappy case so bank on getting no more than 15%.

A 6750/5750 is also okay for gaming at 1080p, although you're skating on thin ice. (But with consolification in games, you can probably keep skating all the way till the next console generation). Overclock it 15% and it's basically as fast as a stock 6770/5770 which is fine as I just said. Most models still need a 6-pin PCIe connector.

I wouldn't bother with a 6670 unless you game at 1680x1050 or below, in which case it's fine. This gives you an idea of how it stacks up, which is to say, it doesn't: http://www.techpowerup.com/reviews/ASUS/HD_7750/26.html

Also, I most definitely did not say VRAM is the primary factor in determining video card performance! What the heck? I did say that system RAM beyond 3GB will not materially improve your gaming experience. The GPU is the primary factor in determining video card performance.

That 6750 2GB card you linked to is a joke. Adding more VRAM, especially slow VRAM, to a slow card doesn't do anything because the memory is not the bottleneck, the GPU is! If the GPU is struggling to render a game at fast enough framerates, then extra VRAM is useless except when used as a marketing gimmick. A 6770 1GB will beat that 6750 2GB card in every way that matters. The only time the 6770 1GB will not beat the 6750 2GB card is when both cards offer unplayable framerates anyway (below 30 frames/second).


Whoa. Getting more confused. Okay, I snapped an image of the PC interior with my tablet. I can't seem to embed it, so I just made it public on my Flickr:
http://www.flickr.com/photos/70978589@N05/6913829388/
If you want to see any vector or component in more detail, just specify, and I'll take more photos.

I presume you're talking about the one he calls a "4 Pin Peripheral Power Cable" and which he notes is commonly called a "4 Pin Molex Cable":
peripheralpic.jpg


Now that you mention it, I can't find anywhere on the motherboard to plug this in. I checked everything including near the CPU and its fan, and I can't find a port with 4 steel teeth like in the above photo anywhere. I know my Flickr photo only shows the face of the motherboard, but you can double check (it's the big white casing in the middle, slightly upper-right). There's only a DVD-player, no CD-ROM, maybe it was meant to connect to that? That appears to be an HDD in the image above. The cables are very short. They can't reach the bottom of the motherboard. Where you see them in my Flickr photo is the extent of their range- at least as they are. So it would need some kind of extension to reach where my hard drives are stored at the bottom left.

I'm a bit concerned about this because I need those 5 Amps if I don't upgrade this PSU, and I would really prefer not upgrading.

I'm just going by the rubric in the table on the referenced page:
http://www.playtool.com/pages/psuconnectors/connectors.html
Even though these are included in the "PCI Express 2.0" box, the only listed cables in that class that actually include the term "PCI Express" in their title are the 6 pin and 8 pin. I think this is just semantics at this point. I understand that I'm going to need a 6-pin or 8-pin adapter depending on the card I choose since I don't see one anywhere in my PC and these video cards require them.
You still don't think I need a new PSU for the 6850 to be safe? Even requiring molex adapters?

Actually, not a bad thought since I'm still uncertain if my PSU can safely power the 6850. If not, despite the 7750's lack of value, it's cheaper than a new PSU + 6850, especially out of pocket. And there's always the chance it drops to $105 plus a $20 rebate or something, so I appreciate the mention.

Since BlastingCap mentioned VRAM as the primary attribute determining gaming performance (on the same CPU), I also noticed a cheap 6750 2GB on J&R. I present these as my video card options:

Asus Radeon 6850 (NewEgg: $130 after $20 rebate)
Max= 127 Watts
http://www.newegg.com/Product/Produc...82E16814121419

XFX Radeon 6750 2GB (J&R: $82)
Max= 86 Watts
http://www.jr.com/xfx/pe/XFX_HD657XC...ductTabDetails

Sapphire Radeon 6670 1GB (Amazon: $55 after $15 rebate)
Max= 63 Watts
http://www.amazon.com/Sapphire-Radeo.../dp/B005HH35KS

Sapphire Radeon 7750 (Amazon: $110)
Max= 55 Watts
http://www.amazon.com/Sapphire-11202...3961871&sr=8-2


Note: Looks like the XFX 6850 that was $120 after the rebate cleared stock. I've been watching, and I've noticed NewEgg typically runs its best rebate specials the first 1-2 weeks of the month.
 
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birthdaymonkey

Golden Member
Oct 4, 2010
1,176
3
81
I agree that a 7750 is a bit overpriced. But since it's the lowest power card that offers decent gaming performance and virtually guarantees OP won't need a PSU upgrade I think it's worth considering. Also, while they may ultimately be better value/money, most of the 6770 and 6850 deals require a MIR.
 

Madmick

Member
Apr 7, 2012
144
0
76
Okay, I get it. I thought dma was advising that my PSU probably couldn't handle the 6850 safely if I needed adapters (due to additional current loss or something like that), but it appears he was just trying to prevent me from buying a card I couldn't support because it would require extra legwork to get those adapters.

All things considered I think that 7750 is my best bet. I'll just wait until a rebate/sale drops it below $100. Too bad. This 6870 is $130 until tomorrow after the -$15 coupon code and -$30 rebate:
http://www.newegg.com/Product/Produc...82E16814150561
That's a pretty freaking sexy sale. Makes the CX430 even more attractive. Jesus, it's like the guys at NewEgg are inside my head!


I did have one more question for knowledge's sake in case I ever do again consider upgrading my PSU; it's in regards to my motherboard:
You will need a 6 pin PCIE which will eventually terminate at this.
I can't find a termination port like that anywhere on my motherboard. You mentioned that you only saw a single molex adapter in my Flickr photo, but let's suppose I had two or had that rare adapter.

Is it possible my motherboard doesn't even support 6 Pin PCI-E? Or is that termination port on the video card itself?
 
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blastingcap

Diamond Member
Sep 16, 2010
6,654
5
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Okay, I get it. I thought dma was advising that my PSU probably couldn't handle the 6850 safely if I needed adapters (due to additional current loss or something like that), but it appears he was just trying to prevent me from buying a card I couldn't support because it would require extra legwork to get those adapters.

All things considered I think that 7750 is my best bet. I'll just wait until a rebate/sale drops it below $100. Too bad. This 6870 is $130 until tomorrow after the -$15 coupon code and -$30 rebate:
http://www.newegg.com/Product/Produc...82E16814150561
That's a pretty freaking sexy sale. Makes the CX430 even more attractive. Jesus, it's like the guys at NewEgg are inside my head!


I did have a few question for knowledge's sake in case I ever do again consider upgrading my PSU concerning my motherboard:

I can't find a termination port like that anywhere on my motherboard. You mentioned that you only saw a single molex adapter in my Flickr photo, but let's suppose I had two or had that rare adapter.

Is it possible my motherboard doesn't even support 6 Pin PCI-E? Or is that termination port on the video card itself?

4-pin MOLEX is usually for case fans, old hard drives, old CD/DVD-ROM drives, and VERY old video cards.

6- and 8-pin PCIe is almost always for modern video cards, which in the last several years have transitioned away from 4-pin MOLEX. It is NOT for motherboards. We've told you this repeatedly. Motherboards take their power from 20 or 24 pin connectors, and sometimes from additional 4 or 8 pin connectors: if a plug looks like a 6-pin PCIe but with a squarish 4-pins instead, it's a ATX12V connector meant for your CPU/CPU Fan. It's a squarish plug unlike the rectangular 4-pin MOLEX plug. Sometimes ATX12V connectors come in pairs for compatibility with boards that need 8-pin.

I suggest that instead of asking the same questions over and over and possibly destroying your motherboard because you're plugging stuff in the wrong places, familiarize yourself with plugs here: http://www.directron.com/psuglossarypic.html It's not as comprehensive as the other page, but it is more up to date.

And yes a 7750 is a decent/good buy at $100 or less (and will save you a few dollars per year because it's one of the most efficient video cards ever made, to date). It's still not a "great" deal because you can get higher performance/price ratio with used or even new 5770/6770 or 6850 parts. On the other hand, a new 7750 does not need a PCIe connector because it draws all the power it needs from the PCI express slot itself (its killer feature in your case, I guess), would come with a warranty, and has better power/thermal/noise if you get one with a decent cooler. (The reference 7750 with tiny cooler is a bit noisy.) You may want to read Newegg reviews to see what people say about how noisy a particular model is.
 
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Madmick

Member
Apr 7, 2012
144
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6- and 8-pin PCIe is almost always for modern video cards, which in the last several years have transitioned away from 4-pin MOLEX. It is NOT for motherboards. We've told you this repeatedly. Motherboards take their power from 20 or 24 pin connectors, and sometimes from additional 4 or 8 pin connectors: if a plug looks like a 6-pin PCIe but with a squarish 4-pins instead, it's a ATX12V connector meant for your CPU/CPU Fan. It's a squarish plug unlike the rectangular 4-pin MOLEX plug. Sometimes ATX12V connectors come in pairs for compatibility with boards that need 8-pin.

I suggest that instead of asking the same questions over and over and possibly destroying your motherboard because you're plugging stuff in the wrong places, familiarize yourself with plugs here: http://www.directron.com/psuglossarypic.html It's not as comprehensive as the other page, but it is more up to date.
Whoa, Blasting, don't get frustrated. You've been incredible in this thread. I'm reading everything you write repeatedly and carefully. I already understood that the 6 Pin PCI-E drives the video card, but I was only unclear if the terminal port was on the video card itself or on the motherboard (which I thought might somehow distribute the power to the video card). I read what you wrote:
6-pin PCIe = almost always used for video cards. The 6850 needs one six-pin PCIe connector like the one you show on the left. 6-pin PCIe can power up to 75W. The 6850 gets the rest of its power from the PCI-Express slot itself.
Just keep in mind that I'm new so I'm being agonizingly exhaustive because I don't have things like the actual 6850 in front of me to look at, and I've never dealt with PCI-E before, and I would prefer to not blunder with a purchase. I'm just safeguarding against my own ignorance, here, in case I considered a future upgrade. It wasn't obvious to me from the above quote that the 6 Pin PCI-E terminal port wouldn't be in the motherboard itself, and the similarity of the ATX12V port that is on the motherboard gave me pause. I can tell that you're only trying to educate me as objectively as possible and I couldn't possibly be more appreciative of your time and advice. You've easily been the most informative poster in this thread.

As dma pointed out, though, I only have one 4 Pin Molex Connector. Even assuming I could get this:
Based on what you said about a 60W maximum via this adapter I didn't think the Radeon 6850 would run. And when I Googled to see if I could buy this single adapter cheaply (as an alternative to upgrading the PSU for running the 6850), I turned up this:
https://bitcointalk.org/index.php?topic=51740.0
That's why I figured the 7750 would be a safer bet, not because I wasn't interpreting what you've been writing on adapters; on the contrary, it's because I've read your posts so many times that I didn't really regard this single adapter as a plausible solution.
 
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blastingcap

Diamond Member
Sep 16, 2010
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Whoa, Blasting, don't get frustrated. You've been incredible in this thread. I'm reading everything you write repeatedly and carefully. I already understood that the 6 Pin PCI-E drives the video card, but I was only unclear if the terminal port was on the video card itself or on the motherboard (which I thought might somehow distribute the power to the video card). I read what you wrote:

Just keep in mind that I'm new so I'm being agonizingly exhaustive because I don't have things like the actual 6850 in front of me to look at, and I've never dealt with PCI-E before, and I would prefer not making a mistake with a purchase. I'm just safeguarding against my own ignorance, here, in case of I considered a future upgrade. It wasn't obvious to me from the above quote that the 6 Pin PCI-E terminal port wouldn't be in the motherboard itself, and the similarity of the ATX12V port that is on the motherboard gave me pause. I can tell that you're only trying to educate me as objectively as possible and I couldn't possibly be more appreciative of your time and advice. You've easily been the most informative poster in this thread.

As dma pointed out, though, I only have one 4 Pin Molex Connector. Even assuming I could get this:

Based on what you said about a 60W maximum via this adapter I didn't think the Radeon 6850 would run. And when I Googled to see if I could buy this single adapter cheaply (as an alternative to upgrading the PSU for running the 6850), I turned up this:
https://bitcointalk.org/index.php?topic=51740.0
That's why I figured the 7750 would be a safer bet, not because I wasn't interpreting what you've been writing on adapters; on the contrary, it's because I've read your posts so many times that I didn't really regard this single adapter as a plausible solution.

If I sound frustrated, it's because I am repeating or even re-repeating myself at this point, and even the single vs. double MOLEX to PCIe discussion is a retread.

I don't really need to post on these forums so it's my own fault, therefore for the sake of your sanity and mine, I'm going to just leave you with a crystal-clear recommendation that can't be installed improperly even if you tried: buy the 7750 and seat it into PCI Express slot. There. You are done.
 

Madmick

Member
Apr 7, 2012
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Given my single Molex connector woes, Blasting, the other course of action I was considering was upgrading to a much nicer PSU like that Capstone you recommended that is Crossfire ready and maybe scoring that 6870. My reasoning is this: as you mentioned, consolification has greatly diminished the graphics demands of PC games. So the 6850/6870 should power nearly any game until then on max settings. Then there will probably be a steep jump once the new consoles drop. That should be in a few years. At that point, I'll scrap everything but this PSU & Vcard and build a new computer around them. I figure it will be cheapest to add a second 6850/6870 via Crossfire and then all I'll need to purchase will be a new Crossfire-capable Mobo, CPU, and fan (the tower should also work until I choose to add a Blu-Ray burner).

That sound smart? You estimate that Crossfire 6850/6870 will be able to max most games of the next generation?

Considering this plan I double-checked on that Capstone you recommended, but it's out of stock. I noticed they're running 20% discounts on all the Rosewill's until tomorrow. I refined the search for only SLI/Crossfire capable:
http://www.newegg.com/Product/Produc...atedMark=False

Do you think that Green series 530w could handle Crossfired 6870s? It's the cheapest of the bunch at $40 after the coupon code.
If I sound frustrated, it's because I am repeating or even re-repeating myself at this point, and even the single vs. double MOLEX to PCIe discussion is a retread.

I don't really need to post on these forums so it's my own fault, therefore for the sake of your sanity and mine, I'm going to just leave you with a crystal-clear recommendation that can't be installed improperly even if you tried: buy the 7750 and seat it into PCI Express slot. There. You are done.
Yikes. Okay, I'll read all your posts again.

Edit: Why are you yelling at me for getting it right? Here's what you wrote:
4-pin MOLEX = 60W max.
x2 4-pin MOLEX = 120W max.
6-pin PCIe = 75W max.

Therefore:

2 4-pin MOLEX -> 6-pin PCIe is safe.
1 4-pin MOLEX -> 6-pin PCIe is not safe.
Ergo, as per your advice, I disregarded the 6850 due to the fact I have only one 4-Pin Molex connector. dma implied that single 4 Pin Molex to 6 Pin PCI-E adapter as an option with his post, so you should be yelling at him for confusing the newb when you'd already declared that option unsafe.
 
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birthdaymonkey

Golden Member
Oct 4, 2010
1,176
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If you're relatively new to computer hardware, you don't want to get in to Crossfiring anything at this point. Aside from the difficulties it introduces by requiring a powerful PSU (at least 600 watts from a quality brand [not Rosewill] with TWO sets of PCI-E connectors), there are cooling challenges and a host of software/driver issues associated with Crossfire. Also, by the time you're ready to do this, the 68xx series will be getting pretty long in the tooth.

FYI, first tier PSU brands are: Antec, Corsair, Seasonic. There are good models out there by other companies, but those are the only ones I'd recommend across the board.

Just go with the 7750. I have the HIS model in my HTPC and it's virtually silent (in addition to being the cheapest one at the present).

http://www.newegg.com/Product/Produc...Tpk=his%207750
 

blastingcap

Diamond Member
Sep 16, 2010
6,654
5
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Given my single Molex connector woes, Blasting, the other course of action I was considering was upgrading to a much nicer PSU like that Capstone you recommended that is Crossfire ready and maybe scoring that 6870. My reasoning is this: as you mentioned, consolification has greatly diminished the graphics demands of PC games. So the 6850/6870 should power nearly any game until then on max settings. Then there will probably be a steep jump once the new consoles drop. That should be in a few years. At that point, I'll scrap everything but this PSU & Vcard and build a new computer around them. I figure it will be cheapest to add a second 6850/6870 via Crossfire and then all I'll need to purchase will be a new Crossfire-capable Mobo, CPU, and fan (the tower should also work until I choose to add a Blu-Ray burner).

That sound smart? You estimate that Crossfire 6850/6870 will be able to max most games of the next generation?

Considering this plan I double-checked on that Capstone you recommended, but it's out of stock. I noticed they're running 20% discounts on all the Rosewill's until tomorrow. I refined the search for only SLI/Crossfire capable:
http://www.newegg.com/Product/Produc...atedMark=False

Do you think that Green series 530w could handle Crossfired 6870s? It's the cheapest of the bunch at $40 after the coupon code.

Yikes. Okay, I'll read all your posts again.

Edit: Why are you yelling at me for getting it right? Here's what you wrote:
Ergo, as per your advice, I disregarded the 6850 due to the fact I have only one 4-Pin Molex connector. dma implied that single 4 Pin Molex to 6 Pin PCI-E adapter as an option with his post, so you should be yelling at him for confusing the newb when you'd already declared that option unsafe.

Look, I'm not yelling at you, just tired of this topic. And being misquoted. I never said VRAM is the primary driver of video cards, for instance. And I would never recommend Crossfire/SLI if at all possible because a) it is almost always not power-efficient compared to getting a new single-GPU solution, and b) Crossfire/SLI has all sorts of driver problems, microstutter, etc.

I didn't know all specs of your PSU at the time that I said that if your PSU had 2 MOLEX then you can use them together to convert them into a single six-pin PCIe plug. Obviously if you only have 1 plug then that's NOT enough, and I already warned you off going that road.

Your PSU is okay. Delta is okay, it's not junk. It is strong enough to run your CPU, GPU, and rest of your system with no problems other than lack of connectors.

That said, either replace the PSU, or make do with the 7750 which is the fastest, most power efficient card you can buy today that does not need additional power connectors.

Since you are unable or unwilling to spend money replacing the PSU, and it's not clear you know what you're doing anyway, the easiest solution is to get the 7750 and you will be done.

Most games are developed for multiple platforms, including ancient consoles, so they are unlikely to stress a modern gaming PC much. All common computer games, including BF3, Crysis, Metro 2033, etc., will run on a E8400 system with 2GB RAM and a 7750 with 1GB VRAM. Every single one. Period. You might have to turn down the graphics settings a bit in order to get playable framerates on a few games, but the world won't end if you have to play Crysis without anti-aliasing, or at Medium graphics settings.

By the time an overclocked 7750 is too slow for most games, even at Medium graphics settings, your CPU will be too slow as well, and you might as well just sell the entire PC and start over. But the rig you have, with a 7750, will be fine for at LEAST two more years, because that's how long it's going to take for the successors to the XBox 360 and PS3 to show up.


If you're relatively new to computer hardware, you don't want to get in to Crossfiring anything at this point. Aside from the difficulties it introduces by requiring a powerful PSU (at least 600 watts from a quality brand [not Rosewill] with TWO sets of PCI-E connectors), there are cooling challenges and a host of software/driver issues associated with Crossfire. Also, by the time you're ready to do this, the 68xx series will be getting pretty long in the tooth.

FYI, first tier PSU brands are: Antec, Corsair, Seasonic. There are good models out there by other companies, but those are the only ones I'd recommend across the board.

Just go with the 7750. I have the HIS model in my HTPC and it's virtually silent (in addition to being the cheapest one at the present).

http://www.newegg.com/Product/Produc...Tpk=his%207750

I agree on the CF/SLI part, especially as it is not power efficient and requires bigger PSUs as you said.

However, I would never make a blanket recommendation on any brand that doesn't make its own hardware and has used subcontractors of varying quality levels. E.g., Corsair subcontracts out the actual hardware production to multiple manufacturers. Corsair's best PSUs are usually made by Seasonic which is very good, but Corsair has subcontracted out to lesser third parties as well, such as for their "Builder series" PSUs that are still decent, just not as well made and with worse fans and warranties.

Basically I would recommend looking at jonnyguru's recommendations for any PSU you are considering buying and go from there. Yes, model by model. The only exception is Seasonic, which is the best in the business and has no middlemen, so I can recommend any Seasonic PSU, period, for quality, though not necessarily for price or price/performance. Seasonic makes PSUs for Seasonic. End of story.
 
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Madmick

Member
Apr 7, 2012
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Okey doke, I got it. 7750 it is. The reason I don't want to spend any additional money upgrading to mediocre standards is because in I'd prefer saving that for when I build a whole new unit in a few years.

BTW, I didn't properly articulate my understanding of what you said about VRAM. I understood that it didn't matter as much as the card itself; I meant to say that you indicated that VRAM is more important than general system RAM for video performance. That 6750 2GB at $82 was considerably cheaper than the cheapest 6750 1GB I could find ($97 when I posted that although now I see one for $87). So I figured it was a solid buy because I assumed 6750 2GB > 6750 1GB. Perhaps that isn't correct either, and the 6750's general bandwidth is a bottleneck for the VRAM such that it doesn't actually benefit at all from the additional GB of RAM, but 2>1 was my presumption.

Where do I learn who manufactured a specific model of a PSU, Blasting? All I could find was this Tom's Hardware article:
http://www.tomshardware.com/reviews/psu-manufacturer-oem,2729.html

And who would be in your 1st Tier besides Seasonic? Anyone?
 

blastingcap

Diamond Member
Sep 16, 2010
6,654
5
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System RAM needs to be enough for the OS and all programs running, including any games. 3GB for Windows Vista or 7 (or XP) is enough, as long as you close web browsers and other RAM-eaters like that, prior to starting any of the really heavy duty games like Crysis.

VRAM throughput is important for graphics. That said, 1GB GDDR5 at higher clock speeds is fine for 1920x1200 though a little low for 2560x1600 or 2560x1440. Where people run into problems is when they use high-res mods for games, or use very high levels of anti-aliasing, which can go over memory throughput and once that happens your video card will need to borrow resources off the card, which slows down the video card drastically. Stay at something reasonable like 1080p with 4x MSAA and you will usually be fine.

Let me make this really easy for you:

Do you game at 2560x1440 or higher? If no, then 1GB VRAM is enough for you and anything higher is unnecessary for your resolution for now, and probably for the next 2 years. All bets are off once the new consoles come out, though.

Yes, it is true that a game can require more than 1GB VRAM in some cases, which will dramatically slow down your framerates, because the video card then needs to borrow resources from outside the board, which adds too much latency, plus VRAM is way faster than system RAM.

But which scenarios will cause you to break the 1GB VRAM barrier? Usually it's either mods or AA (or both). But is it really necessary to play games with super-high-rez texture packs? Is it necessary to crank up anti-aliasing to such high levels? You get diminishing returns by cranking up resolution textures and anti-aliasing. The first increment helps a lot... going from no AA to 2x MSAA is nice. The next increment is a smaller jump in image quality (2x to 4x MSAA). And you get hardly any real-life improvement in image quality once you go beyond 4x MSAA.

Some people like having lots of VRAM because they think it "futureproofs" their cards. That might be applicable to the highest-end cards, but for a lower-range part like the 6750, it's ridiculous. By the time you actually really need more than 1GB VRAM on a video card, that 6750 will be too old and slow anyway, regardless of whether it has 1 GB VRAM or 100 GB VRAM.

This will be my last post in this thread, I hope I helped, and good luck with your build. I think you're doing the right thing by skimping on hardware now and upgrading the entire thing a few years down the road, when we'll know how stressful the next-gen console port games will be and thus how much we'll need to upgrade our PCs to keep up.

As for your PSU questions, jonnyguru.com. Read his reviews and you will know everything you need to know. Seasonic is good. For everyone else, read the reviews on the particular PSUs you are looking at, one by one. Antec and Corsair do tend to put their brands on good PSUs, that part is true. A few others used to be good too... times change.
 

birthdaymonkey

Golden Member
Oct 4, 2010
1,176
3
81
However, I would never make a blanket recommendation on any brand that doesn't make its own hardware and has used subcontractors of varying quality levels. E.g., Corsair subcontracts out the actual hardware production to multiple manufacturers. Corsair's best PSUs are usually made by Seasonic which is very good, but Corsair has subcontracted out to lesser third parties as well, such as for their "Builder series" PSUs that are still decent, just not as well made and with worse fans and warranties.

Basically I would recommend looking at jonnyguru's recommendations for any PSU you are considering buying and go from there. Yes, model by model. The only exception is Seasonic, which is the best in the business and has no middlemen, so I can recommend any Seasonic PSU, period, for quality, though not necessarily for price or price/performance. Seasonic makes PSUs for Seasonic. End of story.

Yes, you're right of course. I was just trying to keep it simple--and generally the Corsair and Antec PSUs currently on the market are safe buys. I was also trying not to sound like a total Seasonic fanboy by mentioning a couple of other brands--but TBH I will only buy Seasonic for my own computers.

OP, if you're still thinking of shopping for a PSU, buy a Seasonic or a unit that is known to be made by Seasonic and you'll be fine.

But I think you'll be happy with a 7750 and no PSU upgrade for the time being.
 

Madmick

Member
Apr 7, 2012
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http://www.pchcables.com/8insa15pinpo.html
The above is a SATA-to-PCIe6 adapter. I checked on that Playtools page, and it says that the SATA can deliver a maximum of 54 watts on the 12V rail (even less than the 60W by a single adapted 4 Pin Molex cable, and definitely not enough to meet the 75W minimum expected by the PCIe6 cable).

So is the above product just stupid and irresponsible by design (similar to the "rare single 4 Pin Molex adapter" that DMA mentioned in post #34)? That would be my conclusion based on the lessons I learned in this thread, but I thought I'd just check with you guys.