View Full Version : ATI 6970 crashes with full fan speed on L4D2...

12-18-10, 01:33 PM
When i play L4D2 for a while i get this weird problem where my screen would suddenly turn black and the graphics card fan enters full speed and i'm resorted to pressing the restart button to restart my pc.

I never had this problem with my 5870.

Any ideas?


12-18-10, 01:55 PM
Update: I just tested it on black ops and i get the same issue with the screen going black and the graphics card fan going full speed. It must be my graphics card thats faulty or driver issue?

12-18-10, 03:17 PM
It seemed likely the GPU is overheating caused the fan going full speed to cool down to lower temp. Keep on eye on GPU temp.

12-18-10, 03:32 PM
I removed the drivers and cleared out all the left over files in safe mode followed by installing the drivers again. I then ran furmark for 1 hour and the system did not crash.

Furmark results:

Room temp 25c
Average GPU temp 92c
Run time: 1 hour

Now to test with games...

12-18-10, 03:55 PM
just played black ops and the same problem after 15-20 mins of game play. Screen went black and the fan went full speed.

Johnny C
12-18-10, 04:18 PM
Something else in your system might be causing the lockup. I'd say that it's also a distinct possibility that you have a defective card.

12-18-10, 08:12 PM
bad psu?

12-19-10, 06:02 AM
Guys, he's using an Enermax Galaxy 1000W DXX psu which cannot handle newer videocards all that great.

12-19-10, 06:11 AM
Ok i think i found out what caused the problem. With the ati 5870 my system was set to 400 fsb x 9 multiplier with 1:1 ram ratio so i got 800mhz on ram which is the default ram speed. I ran prime95 for a few hours and it was stable with the 5870.

Now with AMD 6970 prime95 makes thread number 4 fail every 20-30 mins, which i assume what caused the system to crash with black screen every 20-30 mins when i play games. Now i have lowered the fsb to 380x9 so im on 3.42 ghz instead of 3.6 with 760 mhz on ram and i also decreased the cpu voltage 1 notch.

With the settings above i have prime95 stable for 9 hours now and still running so im assuming the new settings are stable now with this new gpu. I dont understand why the 5870 allows my system to run on a higher fsb compared to 6970? maybe the 6970 draws more power from the pci-e slot causing some sort of problem or something? i have no idea how they work.

I will let prime95 run for another hour then start testing it with a few games. I'll report back with results.

Johnny C
12-19-10, 08:03 AM
bad psu?


12-19-10, 10:47 AM
Ok that has fixed the problem. Thanks for all the help guys, it's weird how my oc was stable with 5870 and not with 6970.

Johnny C
12-19-10, 01:04 PM
Ok that has fixed the problem. Thanks for all the help guys, it's weird how my oc was stable with 5870 and not with 6970.

It's simply that your PSU is getting weak...next time you have some xtra cash replace it with a good quality PSU

01-24-11, 11:31 AM
Hey kam03. Plz help, I have the exact same problem with my system. Its a new build and I haven't oc at all. I have a AMD Phenom II x4 @ 3.4ghz, ATI HD6870, 2x2GB 1333mhz RAM