Dual PSU setup / Jumping Issues

Fijut · 31 Oct 2011 at 01:49

hello

i've attemped to run two psus at once but am having issues, could be for a number of reasons.

I noticed i was overheating a lot in games, more to the point actually crashing in dx11 games [battlefield 3]

system spec

ASrock 890fxdeluxe3
phenomII x6 1090t black edition
8gb 1033mhz ddr3 RAM
2x HIS ATI Radeon 6970s [flashed 6950s. original problem was not fixed by unflashing]

Power Supplies - 1 650w OCZ Battle, was upgraded previously because of heat issues - this is currently plugged into the motherboard, hard drive and cd drive.

1 850w PSU [was previously running the entire system yesterday before dual psu setup, it should be working], i think it is an Overclockers one, I was a noob and took the pc to a local pc shop when i upgraded, this is the first time i've replaced one myself

- this is plugged into the two crossfired cards, and jumped with a wire cut from a molex cable.

The jumped PSU starts when the PC is turned off but when i turn my PC on everything runs normally for about 4 seconds until the jumped PSU turns off [or at least it's fan stops spinning.
The graphics cards make no beeping noises like they are underpowered, and the fans on the cards move slowly. But the screen receives no input.

If anyone could give me some assistance on Dual PSU setups or why my PC was crashing in the first place i would be incredibly grateful, i really am running out of ideas now.

dcsarge · 31 Oct 2011 at 09:59

Why run two PSUs when a single decent (Corsair/Antec etc.) one would be safer and more reliable?

If you are getting overheating issues running games, isn't it more likely you have insufficient cooling for your CPU and/or GPUs? Have you checked the load temperatures using any monitoring software?

Surveyor · 31 Oct 2011 at 10:04

You really are trying to kill yourself and/or your PC.

As dcsarge says buy 1 quality PSU instead of the 2 rubbish ones you have now.

The Deuce · 31 Oct 2011 at 10:11

you really are an idiot!

scrap that i've just re-read your op.

pastymuncher · 31 Oct 2011 at 10:49

Just get rid of your two crap psu's and buy a decent branded one.

My arguement about retailers selling crap psu's is justified by people like you who build a high end rig and then try to save money by skimping on the psu. It's a false economy!!

andy_mk3 · 31 Oct 2011 at 10:52

I was expecting 3xGTX580's in the spec for dual PSU's!!

As said, buy one decent one before you kill either hardware or yourself.

Fijut · 31 Oct 2011 at 13:19

pastymuncher said:
My arguement about retailers selling crap psu's is justified by people like you who build a high end rig and then try to save money by skimping on the psu.

going a bit far there. it was my first build and i wasn't sure what to get, i ended up with the 650 watts one. Keep in mind at the time i wasn't confident enough to even put together the pc myself. It turned out the pc cut out after an hour on games so i took it to a local pc repair place, not a big retailer, and they put in the 850watt psu but i still have the same problem with dx11 games - i don't think it's the powersupply, i think it's cooling.

I put back the 850w PSU and ordered a custom CPU cooler and will take it from there.

pastymuncher · 31 Oct 2011 at 13:28

It's not going a bit far at all. If people did their homework before building a rig they would know not to skimp on the psu. Computer forums are full of posts with people having problems with psu's because they skimped on it. There are even more post's with people recommending quality psu's. You would'nt go out and buy a cpu, graphics card or motherboard without doing some research would you? The same thing goes with psu's. There are enough review sites out there and Jonnyguru's is probably the best.

Cheap psu's will never put out their claimed wattage, are built down to a price using crap components, have weak, possibly unstable rails, are horribly innefficient and when they fail are likley to take out some or all of the rig with them.

There is no excuse for buying a cheap psu for a mid-high end rig.

cavemanoc · 31 Oct 2011 at 13:29

Wow - all a bit aggressive today. There is nothing intrinsically wrong with running 2 (or more) PSUs, I have done it several times in the past (sometimes as I needed a specialist PSU - like a meanwell to run my TEC - other times as it was a custom build that needed something a little different.)

I will agree that a poor PSU is nothing but trouble in the long run - especially if you are running high end kit - it would be a real shame to blow £500+ worth of kit for the sake of a £100 PSU

If you are happy with your PSUs though, I would recommend using a relay (as found here) - it's far slicker than the old paperclip trick an works very nicely!

pastymuncher · 31 Oct 2011 at 14:55

Your OCUK Battle 650w psu is made by Powercool and from what i have dug up it has dual 12v rails, one rated at 14A and the other at 16A. By my reckoning that gives you a pathetic 360w on the 12v rails which is nowhere near enough power for your rig.