Nvidia 9800 GX2 Help?

[draee]

I've had a problem since installing my new GX2 card... Before i had an 8800 ultra and my games were running fine (ish, till i started getting that damn nvlkdm error) but now, for some reason my fps is great but when i play (crysis, warhead, airborne) the game stutters alot? if u dont know what i mean then basically, the fps is perfectly fine but the more i play the game it just detoriates in quality, not in terms of the graphics but it just keeps stuttering. stutter as in crashes for a mili second constantly. After posting on a website i was told that the problem is my PSU is not powerful enough and if i keep playing, my card will detoriate in quality. Is this true? I am quite convinced this is probably the case but i need some more expert advice. My set up is:

video card: gefroce 9800 gx2
cpu: intel core 2 duo 6700 @ 2.66 ghz
mboard: nforce sli 680
ram: 4 gigs
psu: 620watt corsair

could it be that my PSU is not strong enough to handle the card and leads it to overheat, leading to crashes and stutters? PLEASE HELP! peace!

 

[DaMak420]

If it aint on this list, i wouldnt be using it!
http://www.nvidia.com/object/geforce_9800gx2_pwr_supply.html

 

[draee]

so your saying these psu's are the only ones that will surely work for the gx2?

 

[DaMak420]

they are approved by the manufacturer. I can't tell you that another PSU wouldn't work,but I can tell you, the ones on the list will.