GTX 570 Classified's SLI power configuration..?

[CLeRiCNovA]

Hello all

I got an SLI question pertaining to the power connectors. Before i ask here is my system details.

CPU: i5 2500K (gotten to 4.9 @ 1.41v older s775 Thermalright ultra-90 cooler)
Mobo: Asrock Extreme4 Gen3
Ram: 16Gb G.Skill Sniper. Low Voltage 1.35v
Gfx: EVGA GTX 570 Classified (hit 980 on core @ 1.113v stock vram speed)
PSU: Antec HCG 750w 62amp max, 4 12v Rails @ 40 amp

I run it everyday at 4.0ghz cpu and stock on the gpu. No need to do serious OCin yet. Unless i get bored and do a Kamakazie Run in 3dmark.

Any way I ordered a second GTX 570 Classified(backordered, but i believe i got one coming) My question is since I have a 4 -12v Rail design on my psu would it be best/ok to hook up the 6,8 pin power to the cards in a cross(x) style configuration. As in one 8 pin from one lead goes to one card while the 6 pin from the same lead goes to the other card. the same for the other lead, 8 pin to one card 6 pin to the other card. Only reason i ask is to avoid the big loop that occurs when hooking both the 6 and 8 pin from 1 lead to one card. my psu wires are hard to bend between the 6 , 8 pin and I'd rather avoid it, plus i think it would look better like an X between them instead of a round loop from both cards.

I havent looked into it much. Asked a few friends. I'm not sure it will fit lenght wise. I'll see when the card shows up. Any help would be appreciated.

 

[EvilJoker]

It does sound like a good idea, But i dont think the PSU would be really happy about it. Seems like it would have to adjust the power between the 2 leads,, May cause your PSU to run harder than it needs to,(Just my opinion)

 

[CLeRiCNovA]

thanx for the reply. I am looking for opinions really so yours is greatly appreciated.

I think i might call Antec see what they say about it. I did read that since it is a 4 rail design that it doesnt matter as much which leads are used and such.(very complicated article on single rail vs multi rail) The article stated the only time a multi rail might be bad is if u are spinning up 10 hdd's or something like that. Not from a pair of gpu's or even a quad setup.

I'll call Antec eventually and post what they say for anyone interested if its a good or bad thing to do.

 

[EvilJoker]

It might be safe to do. I just wouldnt do it. But let me know what Antec says

 

[EarthDog]

It may be, like a lot of PSU's these days, that this is really a single 12v rail CPU in that there is no OCP on each rail (so any one rail can pull rated power). This one however, I believe is shunted on each rail...so it looks to be a quad rail PSU. That said, doesnt look like you have much choice in which rail you want it to run off of, do you? I dont see any labels on the connectors showing which rail is which so....... PLug it in and go. Plenty of power in that PSU to run 2 570's.

I have called in help.

EDIT: Opinions are fine, but this is something you dont want people guessing at. If it was what GPU should I get, +1 for opinions, but PSU's and people guessing (including myself) not a good idea.

 

[EvilJoker]

+1 With ED

 

[Bobnova]

You can mix and match the wires however you'd like, 40 amps is 480 watts, plenty for two gtx570s even if you somehow get them on the same rail.

The PSU doesn't adjust "power", nor does it have any individual control (voltage or otherwise) over the various 12 V rails at all.

It's theoretically possible to have interesting resonance issues, but I seriously doubt it would happen even if you were drawing a TON of power with no input filtering.
You aren't, and those cards have input filtering.

Knock yourself out.
Actually it occurred to me. I've done that before. Works great. No issues.