HD4890 - pc resets itself when playing games - help pls

Hi

Hoping you can help me with an issue.

I've recently built a new build

Have tried installing and playing several games. Literally get a minute or so into the game before system resets itself (no lockup / freeze - just resets).

The games I've tried so far have been World in Conflict, Need for Speed Shift, Battlestations Pacific.

Here's my system
i7 920 - running at 2.67ghz
Asus PT6 SE
6gb ddr3 ocz memory
Sapphire ATI 4890 HD
500W NorthQ PSU 4350GP-FL
Crucial M225 64gb SSD
Windows 7

Does a system reset instantly point towards a obvious culprit?
- memory issue / latency / voltage?
- power supply / overheating / insufficient watts?
- graphics card / driver issue?
- cpu overheating?

I'm thinking that either I have a faulty graphics card or a PSU that isn't up to the job (even though the graphics card says a 500w PSU should be fine). The graphics card is running at stock speeds (870 / 1050)

I've got the latest drivers installed via CCC, so I don't think they're an issue.

thanks

This one:

http://www.scan.co.uk/products/500 [...] Db-Noise!!

Key info :

- 0dB noise under normal conditions
- 12v ATX2.2 standard
- 80 % efficiency
- Green Power certified
- Grid case design for free airflow
- Build-in 70mm smart backup FAN
- ROHS certified
- PCi-Express
- 2 x S-ATA

Lifetime : 50,000 hours at 25°
Dimension:150*140*86mm

70mm BackUp FAN
This FAN only turns on when the temperature reach the limit temperature for FANLESS operation at 65º and will spin until the temperature is below threshold again and turn off

Activate Temperature: 65º
FAN Size: 70 * 70 * 10mm
Rated Voltage: 12 V
Bearing Type: Sleeve bearing
Speed: 3000RPM
Airflow: 31,5CFM
Noise: 25dB(A)

Cable configuration:

1 x 24/20pin ATX cable
1 x 4pin motherboard extension cable
2 x 6pin PCi-express cable
2 x S-ATA plug
4 x Molex plug on 2 cables (2 on each cable)
1 x Floppy plug on molex cable

Manufacturer: NorthQ +12V7 Rail: N/A
Size: ATX 2.2 +12V8 Rail: N/A
Edition: Fanless:
Wattage: 500 W Modular:
+12V1 Rail : 19 A Sli:
+12V2 Rail : 19 A Xeon Support:
+12V3 Rail: N/A EPS 12V:
+12V4 Rail: N/A Motherboard Connector: 20+4 Pin
+12V5 Rail: N/A Connectors: 1 x 4pin ATX 12V
4 x 4pin Molex
2 x 6pin PCI-E Power
1 x FDD Power
2 x SATA Power

+12V6 Rail: N/A Dimensions: - (WxHxD)

this is the graphics card

11150-05-21R - 1GB Sapphire HD 4890 Vapor-X, PCI-E 2.0, 4200MHz GDDR5, GPU 870MHz, 800 Cores, DVI/ D-Sub/ HDMI/ DP

http://www.scan.co.uk/Products/1Gb [...] GB-VAPOR-X

If you can try another PSU, preferably one of a decent brand name (Antec, Corsair, Seasonic, and many others not mentioned) that should be your first diagnostic test.

Not much else you can do, short of wiping your HDD and reinstalling/updating everything. If the problem persists, it is a Hardware issue. With your symptoms (complete computer reboot after a short time gaming) a faulty PSU seems to be the culprit.

Either return the PSU you bought, borrow one, or buy a new one. If it is a faulty PSU, nothing short of a replacement will diagnose/fix the issue.

ps - i reinstalled W7, rand 3dmark vantage and same issue occurs

If the graphics were slow, and full of artifacts (obvious graphical glitches) then the card might be a culprit. But complete restarts, especially repeatable shortly after starting a higher power task (like a graphically intensive game) screams PSU issue. I can't tell you how to obtain another PSU for testing, but you definitely need one. If it is a new build you should be able to return it for a replacement/credit at the least.

A good PSU doesn't have to be even as high as $100:
http://www.newegg.com/Product/Prod [...] 6817371016
Antec 550w PSU, 64.99 free with shipping. Reliable brand that makes great power.