Single 12V rail psu recommendation??

[kenny_k]

I recently got the ST85F for the 8800 GTX (previously had the OCZ 520Powerstream). It powers the 8800 ok but very disappointed in it's stability for OC'g. I can't get back the OC on the cpu I used to have with the OCZ. I'm thinking of going back to a single 12V rail psu for this reason. Trying to decide between these 3 which are about the same as far as voltages.
PCP&C Silencer 750
http://www.pcpower.com/products/viewproduct.php?show=S75QB

And these 2 newcommers from Silverstone. OP750 and DA750. The OP650 got a good review from JohnnyGuru (none on the OP750). The DA750 appears to be the same as the OP750 except modular???
http://deadeyedata.com/shop/index.php?main_page=product_info&cPath=7&products_id=189
http://deadeyedata.com/shop/index.php?main_page=product_info&cPath=7&products_id=190

[Nebulous]

Without looking at the links, there's no question I would get the PCP&C Silencer 750w. PCP&C is the Rolls Royce of psu's. If I was able to afford one , i would jump on one of these in a heartbeat.

Fine unit, superbly built and the best customer support out there, bar-none.

[CrazyIrish]

I have the 610 and it definitely lives up to its name (Silencer). The fit and finish are as nice as I could ask for.

[meionm]

Are you going to have sli or crossfire setup. If not, then you won't be needing more than 500w.

[greenmaji]

The big enhance OEM PSU's are a bit flakey at this time, the ST75 or 85ZF would have been much more reliable then the ST85F.

You don't need a single rail PSU unless you plan on getting a CPU that needs more then 18 12V amps really (Quad core or heavy overclock on a pressler or possibly a smithfeild) The 8800GTX has two PCIe power inputs/connectors ;)

[kenny_k]

I was thinking the single rail for the OC. I had no problem with my OCZ 520 Powerstream which was a single rail. But when I got the 8800 GTX, I wanted to beef up the psu a little. I chose the ST85F cause I wanted to give modular a try. It powers everything (8800GTX, WC, fans, etc) but I can't get back to the same OC I had with the OCZ. That's why I figured a single rail would be better. I dont think the ST85F is supplying a good current for the cpu. I measured the rails with a multimeter. The +12V1 & +12V2 on both the pci-e connectors are 11.91, however, when I measured the 4pin cpu power it was 11.84 and drops to 11.71 under load.

[RollingThunder]

I was thinking the single rail for the OC. I had no problem with my OCZ 520 Powerstream which was a single rail. But when I got the 8800 GTX, I wanted to beef up the psu a little. I chose the ST85F cause I wanted to give modular a try. It powers everything (8800GTX, WC, fans, etc) but I can't get back to the same OC I had with the OCZ. That's why I figured a single rail would be better. I dont think the ST85F is supplying a good current for the cpu. I measured the rails with a multimeter. The +12V1 & +12V2 on both the pci-e connectors are 11.91, however, when I measured the 4pin cpu power it was 11.84 and drops to 11.71 under load.

I would put your OCZ back in and use it.

[Super Nade]

Without looking at the links, there's no question I would get the PCP&C Silencer 750w. PCP&C is the Rolls Royce of psu's. If I was able to afford one , i would jump on one of these in a heartbeat.

Fine unit, superbly built and the best customer support out there, bar-none.
Built by Seasonic if I may add. ;) Going by the OEM, I'd pick something that is cheaper, like the Corsair units or if you can find it, the Silverstone Zeus ST56ZF would be a very good buy. If you decide that efficiency is a prime requirement, you can try the sub 600W Enhance units.

A few other options would be the OCZ Evostream, which although expensive, is built like the proverbial tank.

[RollingThunder]

Built by Seasonic if I may add. ;) Going by the OEM, I'd pick something that is cheaper, like the Corsair units or if you can find it, the Silverstone Zeus ST56ZF would be a very good buy. If you decide that efficiency is a prime requirement, you can try the sub 600W Enhance units.

A few other options would be the OCZ Evostream, which although expensive, is built like the proverbial tank.

S/N,

Would you say it's safe to say that running one 8800 is close to running two 7900s, and if a decent rated SLI like this Corsair 520HX should run a single 8800 with ease?

We are seeing a pattern of those buying an 8800 jumping to the big 750 / 850 w power supplies when in fact much less ($) would run an 8800 with ease and in many cases their original power supply if of good quality would be more than enough for an 8800.

Are you seeing all this about the same?

[Gautam]

I must say that the Corsair HX's are very impressive. (They're single rail in reality) If you want modular, there's no better option out there. AFAIK the PCPC Silencers are basically the same under the hood, but without the 120mm fan and modularity.

The Olypmias look quite promising as well.

[Super Nade]

S/N,

Would you say it's safe to say that running one 8800 is close to running two 7900s, and if a decent rated SLI like this Corsair 520HX should run a single 8800 with ease?

We are seeing a pattern of those buying an 8800 jumping to the big 750 / 850 w power supplies when in fact much less ($) would run an 8800 with ease and in many cases their original power supply if of good quality would be more than enough for an 8800.

Are you seeing all this about the same?
There are a few things one must take into account here. Running 2x cards in SLI does not equal double the power consumption. It does not seem to scale linearly, although you would be safe in assuming so. Technically, a good 450-520W unit should be able to run an 8800GTX SLI setup with ease. Indeed, a unit like the Silverstone Zeus ST56ZF has done this (as domnick32 ran his setup). 750/850 W units are a bit of an overkill. You may need those with a hog of a board like the 4X4. Chipset power consumption is often overlooked in calculations. It is more important than CPU consumption, IMO.

So, for a single card, a good 400W unit would suffice. :)

That being said, don't plug your PowMax to test this out. It may be rated as 450W, but in reality it's probably 45W. :D

[greenmaji]

If I was to recomend a seasonic OEM unit right now it would be the Corsair HX units (wich happen to be single rail and modular), single 8800GTX and a C2D or AMD the 520W should do but I would step that up to the 620W if Kentfeild is in your upgrade plans for that rig.

Any of the Silvertone ZF's (none of wich are modular) would be solid choices though :thup: