PSU 12V Rail Low

Solaris · 17 Nov 2012 at 19:58

So I put together a new rig (budgeting myself quite a bit) this week.

The parts arrived, I built it, it runs fine.

Now and then (only during gaming so far) it reboots. No error messages, nothing in the logs, it just reboots.

I've been watching the voltages whilst gaming for the last hour and at times the 12V Rail fluxuates really heavily when the computer is loaded (getting down as low as 11.215V.

Do you think low voltage could be causing the reboots? Or am I just being paranoid?

Solaris · 17 Nov 2012 at 20:12

Seen it go down to 11.071 now... This is meant to be a 750W PSU and there is nowhere near 750W of load on it...

cammy5477 · 17 Nov 2012 at 20:18

what psu is it and what are your system specs?

Solaris · 17 Nov 2012 at 20:20

EVGA GeForce GTX 660 Superclocked 2048MB GDDR5 PCI-Express Graphics Card
AMD Piledriver FX-8 Eight Core 8350 Black Edition 4.00GHz (Socket AM3+) Processor - Retail
Asus M5A99X EVO AMD 990X (Socket AM3+) DDR3 ATX Motherboard
OcUK Swift 750W V2 Silent Power Supply
2x Corsair XMS3 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit (CMX8GX3M2A1600C9)

Griff7520 · 17 Nov 2012 at 20:24

I think the psu is not up to the job....no matter if it is a 750watt.....got some nice kit there but the psu is letting you down...imho

BuToNz · 17 Nov 2012 at 20:37

Solaris said:
OcUK Swift 750W V2 Silent Power Supply

Ouch, wouldn't trust that PSU in any system. Return it as faulty and ask for an upgrade, something from Seasonic or Corsair will do nicely.

liamcrane · 17 Nov 2012 at 21:21

what you using to measure the 12v rail voltage? SOftware can be known to take false readings so to be 100% sure if you have a multimeter handy take the 12v reading from the 24 pin plug with a game running and see how it reads.

Does sound like a PSU issue tho going by random reboots when doing intensive taks like gaming

cammy5477 · 17 Nov 2012 at 21:50

100% psu mate
get rid pronto and get a seasonic/corsair/xfx like butonz said.
That psu may be able to peak 750w but theres no way under pressure it could sustain it stable.

Rooster212 · 17 Nov 2012 at 21:54

yeah your problem is the fact it is a cheap PSU, all cheap PSUs will have issues like that!

Rooster212 · 17 Nov 2012 at 21:57

Here are some possible replacements (if you don't want to SLI/Crossfire)

YOUR BASKET
1 x Seasonic S12II 520W '80 Plus Bronze' Power Supply £54.98
1 x Corsair Builder Series CX 500W V2 '80 Plus Bronze' Power Supply (CP-9020047-UK) £49.99
1 x XFX Pro 450W Core Edition '80 Plus Bronze' Power Supply £43.99
1 x Antec VP450P 450W '80 Plus' Continuous Power Supply £36.98
Total : £198.55 (includes shipping : £10.50).

lee32uk · 17 Nov 2012 at 21:58

You have essentially bought a Ferrari and put a Lawnmower engine in it

Like everyone else has said, you should change it for a well known brand.

Solaris · 17 Nov 2012 at 22:27

Cheers for that guys. I do plan to SLi in the future so will have to go with a 750W+ but will defo get a good one this time.

OptimaLnrg · 18 Nov 2012 at 07:25

I honestly don't understand why ocuk sell these oem BS psus. Tbf their competitors sell these same things with their own name..

RetrogamerX · 18 Nov 2012 at 07:35

XFX is amazing single rail PSU.

Rooster212 · 18 Nov 2012 at 10:35

Here are some PSU choices for SLI.

YOUR BASKET
1 x Cooler Master Silent Pro Modular 2 720w '80 Plus Bronze' Modular Power Supply £104.99
1 x Seasonic M12II 750W '80 Plus Bronze' Modular Power Supply £99.98
1 x Corsair Enthusiast Series TX 750W V2 High Performance '80 Plus Bronze' Power Supply (CP-9020042-UK) £94.99
1 x XFX Pro Series 750W XXX Edition Modular '80 Plus Bronze' Power Supply £79.99

Solaris · 18 Nov 2012 at 11:30

So, I was just using the computer for some work stuff (don't really have a choice, I'm an on call systems administrator that needed the computer to VPN into work) and bang (literally) and the computer turns off...

Try to turn back on and the Mobo has LEDs showing on it, but no activity...

Get out the multimeter and the 12V rail is now showing 0V...

OcUK Swift 750W V2 Silent Power Supply - Lifespan <1 week...

Lesson learned, don't cheap out on the PSU...

Because I didn't have a choice as I really need the computer for work... Had to fork over money to the Purple Shirts for a new Antec PSU... Sad day...

Nightglow · 18 Nov 2012 at 11:36

Always, always build a pc around a well known quality branded psu, Corsair,BeQuiet, Antec, etc.
Never use generic psu's, you can & will mostly likely will end up with an expensive bill, replacing motherboard,etc when it fails & takes out other parts.

Solaris · 18 Nov 2012 at 11:46

Yeah, luckily this time there was no collateral damage. Board, CPU, GFX, Disks, etc all look fine...

Just watched the voltage during a game of BF3 and didn't dip below 11.943... Big improvement.

J-FRO · 18 Nov 2012 at 12:31

Lucky escape this time. What Antec PSU did you get?

Solaris · 19 Nov 2012 at 13:05

Antec VP550P 550W '80 Plus' Continuous Power Supply