Dual Rail or not to Dual Rail?

Doppleganger · 30 Mar 2006 at 23:43

Hello all.

I'm in the process of upgrading my PSU. My trusty old FSP (Sparkle) 400-60FPN is doing a great job of powering an 7800GTX SLI rig but the 12v rail (according to the inaccurate MBM) is falling to as low as 11.38v. Also, my core voltage is dropping on full load from 1.66 to 1.58v, meaning my overclock is potentially no longer stable. However, I've only had one crash when running full load and that was a sound-skipping issue in Oblivion. I'm fairly sure it's linked to my struggling PSU and not a bug in that game but I'm not certain..

Anyway, I've been reading reports on the fact that it is better to have a beefy single rail PSU rather than dual rails for an SLI/Crossfire system. In fact some 7900GTX SLI rigs are not stable on dual rail PSUs.

So, should I buy a single rail PSU rather than a dual rail one and if so, what PSU?

Cheers for any help.

Doppleganger · 31 Mar 2006 at 17:04

Ok, after reading some of your replies and doing some further searching I've settled on one of these 2 PSUs to replace my old Sparkle:

Akasa Ultra Quiet 650W PowerPlus Active PFC ATX2.0 PSU - Black Nickel (CA-015-AK)

OR

FSP Sparkle FX600-GLN Epsilon 600W ATX2.0 PSU (CA-002-SK)

Both are 4 rail PSUs and I've heard good things about the Akasa and I'm a fan FSP Sparkle PSUs in any case.

Cheers.

Doppleganger · 31 Mar 2006 at 17:38

Street said:
Never trust any software measurement programs... Get a multimeter and test it that way.

I know that MBM (or any other voltage measurement programs) isn't entirely accurate. I'm basing my need for a new PSU because basically my 400watt Sparkle is not really up to the job of powering a 7800GTX SLI system with 3 HDDs and 1 optical drive.

It's doing a fine job atm but sooner or later it's gonna fall over.

Doppleganger · 31 Mar 2006 at 20:33

Cheers for all the help guys!

Doppleganger · 11 Apr 2006 at 01:17

I went for the Akasa Ultra Quiet 650W PowerPlus in the end. Big hefty psu with 4 12 volt rails and good reviews. Should be more than enough for when I upgrade to a dual-core cpu. The only slight downside is the fan is slightly on the noisy side.