9600 GSO Sli HELP?

[Mac84Kellar]

Im trying to run my two 9600 GSO 384mb vga's in Sli.
I have a EZCOOL PS-900 Tornado 800w psu and q6600 cpu. When trying to play game (L4D2) my computer switches itself off.
Can anyone explain why?
I thought this PSU would be powerfull enough for my rig?

 

[MeatLoaf]

Welcome to the forums.

Have you checked each card by itself to rule out a faulty card

 

[JonJ678]

The psu may well not be. EZ cool's idea of 800W is unlikely to correlate with reality, let alone match it. I'll see if I can find the specs for your one online

Manufacturer specs of
22A at 12V on two rails
38A at 3.3V
40A at 5V
Which in fairness does come out at 850W. It's a shame that almost nothing uses either 3.3V or 5V anymore, so in practice you have two 260W 12V lines. One of these has the cpu on, the other is probably feeding both graphics cards. So nominally you should be ok, a 9600gso should pull under 100W full load.

Unfortunately the above ratings are apt to be at 25 degrees C, i.e. optimistic as soon as the psu warms up. It's also possible that it can't do 22A on both 12V rails at once, even at 25 degrees. I think there's a good chance your psu is incapable of doing this. Turning off to protect itself when more power is needed than it can supply would fit too, as it turns off when gaming.

Does it also switch off if you try to run furmark?

 

[Mac84Kellar]

furmark ran with no problems. Any other ideas? Can u suggest another psu which will be able to cope with this or should i buy 2x xfx 250gts green ed?

 

[jigger]

First off, pull one card and try the game.

No point in buying a pair of gts250's or a new PSU if you don't know why your current setup isn't working.

 

[Mac84Kellar]

I have tried both card by themselves and they work fine. Is it just the psu. Can anyone suggest a new one for under £100?

 

[jigger]

Whats your full system specs and drivers are you using ?