Shut Down in Games

[piemasterp]

I just upgraded my computer with a new PSU and Graphics Card. When I enter GTA IV, I can play for a while, but then the computer shuts down. I can turn it back on immediatly afterwards. I believe this is either the PSU or the Card, but I dont think the card is overheating, since I have it stock, no OC. Its a Zotac GTX 460 2GB, and my PSU is a Rosewill Xtreme 750. This started the first time I played a game since I installed the new components, and the first time I ran it for around half an hour. The second time I opened GTA IV, I could not login to Windows Live (Unrelated?) and just got into the game when it shut down. My Idle GPU temp is 31 degrees, and my Phenom II x4 840's is idle at 23. Could my PSU be not getting enough airflow? Its a new case too, with a bottom mounted PSU, so I mounted the fan down to suck in cold air from under the case. Should I have both PCIE 6 pin connectors from the same rail or different rails? Also, could it be my HDD failing, or a bad connection to the HDD? Sorry for the question overload, but I want to be able to use my new computer before school starts up again next week

EDIT: Max gpu temps i saw in a 15 min gaming session was 60 C

 

[jsc]

First rule of upgrades is when something goes wrong, you stop, restore the original parts, and recheck your system.

Second rule is, if possible, upgrade only one component at a time.

So, what were the original parts that you replaced?

 

[piemasterp]

I upgraded my PSU and Graphics card. My old PSU was a 430 watt Thermaltake, and my old graphics card was an 8800GT. I will try to take out the graphics card and try my old one with the new psu now. Incase it helps, last night i did a furmark test, and it shut down after 5 min of running at 72 degrees max. I'll tell you what happens when I put in the old card.

 

[piemasterp]

Ok, I tried my old graphics card in furmark for around 3 minutes, then the temperatures got to 95 degrees so I called it quits. In those 3 minutes it didn't show any signs of slowing down though. Could my GTX 460 be a bad card, or is it not recieveing enough power/not enough amps? The PSU is quad-railed, with 4 pcie 6 pin over 2 of those rails. Should my two connectors be from the same rail or different?

EDIT: I ran GTA IV on all low settings with my 8800GT, and the computer shut down within 5 minutes. Should I file an RMA for the PSU with Newegg?