Crash when playing games

About a month ago, I built a computer (specs listed at bottom). I made certain to research the compatibility of all the components and check that they will meet the minimum requirements I have for the system (PC gaming). But whenever I start a game, within 1 minute of being in the game (not including pre-rendered video), the audio and video will stutter then the screen will go black and the audio will continue to stutter until reboot. If I open Task Manager and close the game before it goes to a black screen, I do not need to reboot and the computer continues to function normally. This occurs across 2 different games (Crysis and BioShock 2) and occurs regardless of the graphics settings (High versus Low).

I have uninstalled and reinstalled the drivers for the video card and all drivers included with the motherboard. I have searched for the latest driver updates. I have tried running the games with the latest video card driver and a previous version. I have reinstalled Windows 7 clean and then reinstalled all the drivers. Despite this, the problem persisted.

I checked all the wiring. Everything is plugged in correctly (8-pin and 24-pin motherboard sockets, 2 6-pin on video card, etc.) I made certain that the memory modules and video card are seated correctly. I reseated the CPU heat sink and reapplied thermal paste.

I tested the CPU temperature with RealTemp and, under full load, the CPU never exceeds 76C on any core. I ran Memtest86x and after 3 passes, none of the memory modules returned any errors. I ran 3D-Mark Vantage Pro and both the CPU and GPU completed all the tests with a 3D-Mark score of H11111. I am a little confused how the computer can run a 3D processing test successfully, yet fail every time I try to run a game.

I have emailed the video card manufacturer (XFX), the motherboard manufacturer (ASUS) and PSU manufacturer (OCZ). After a conversation with XFX, I RMA'd the video card thinking that would solve the problem but it did not. The response from ASUS was that I should breadboard the computer and test each component individually to see if an error occurs. If that fails to isolate the bad component, they suggested I RMA the motherboard. OCZ has not yet returned my email. I wanted to get a second opinion about what to do, so I thought that I would ask here. If I breadboard my computer and still cannot find the problem, could it be the motherboard? Or could it be the PSU? And is there any way I could test one of those two components? I would like to aviod RMA'ing another component without being certain it is the cause of the problem. Any advice would be greatly appreciated.



System specs:
Antec Performance One P180 Silver cold rolled steel ATX Mid Tower Computer Case
OCZ Z-Series OCZZ650 650W ATX12V2.2/EPS12V2.91 80 PLUS SILVER Certified Active PFC Power Supply
ASUS P6X58D Premium LGA 1366 Intel X58 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
Intel Core i7-920 Bloomfield 2.66GHz LGA 1366 130W Quad-Core Processor
XFX HD-585A-ZNDC Radeon HD 5850 (Cypress Pro) XXX Edition 1GB 256-bit GDDR5 PCI Express 2.0 x16
OCZ Gold 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory Model
ARCTIC COOLING Freezer 7 Pro Rev.2 92mm Fluid Dynamic CPU Cooler
Arctic Silver Ceramique Thermal Compound
OCZ Vertex Series OCZSSD2-1VTX30GXXX 2.5" 30GB SATA II MLC Internal Solid State Drive (SSD)
Seagate Barracuda 7200.12 ST3250318AS 250GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive
SAMSUNG Black Blu-ray Combo Drive - Bulk SATA Model SH-B083L/BSBP LightScribe Support
Microsoft Windows 7 Home Premium 64-bit

Check your Direct X version, you probably need to install Direct X 9.