I recently purchased a pair of PowerColor Radeon HD 6870 graphics cards to run in crossfire, and have run into a problem with one of the cards. I have pretty limited knowledge in this area, so please bear with me if my explanation gets a bit long-winded!
I had been running one of the cards for a month without issues before finally getting around to freeing up room on my motherboard to slot the second one in. However, upon enabling crossfire in the AMD control centre, my screen started permanently freezing within ten minutes of startup, forcing me to hold down the power button and force a restart. Disabling crossfire would fix the issue.
After some other trouble-shooting, I got around to testing each graphics card individually. Unsurprisingly, the card that I had been running for a month previously had no problems. However, when replacing it with the second card, connecting it using the same PCIE slot, and the same two power supply cables that the first had been using, I immediately started having what I assume are some sort of graphics crashes.
My screen would turn a completely solid colour, and I would be forced to hold down the power button and manually reset my computer. Iíve been presented with both solid one-colour screens (generally blue, grey, or black), as well as screens striped with two or three different colours. Even though I am unable to see anything, I have found that I am still able to talk and hear my friends on teamspeak Ė once, I was able to converse with them for a full three minutes after the crash occurred before deciding to power off my system.
I have no idea as to why these crashes occur, but they seem to occur more frequently when doing certain activities. For example, I was able to play a full 45 minutes of Dead Space 2 without any problems, and am consistently able to run an entire 3DMark 11 benchmarking test without issues. However, when browsing the internet using Firefox (even just reading forums), I often crash within a few minutes. Running Terraria, which I assume is not overly taxing on the graphics card, almost always causes a crash within a minute.
Thinking that the card must be faulty, I gave it to my brother to test out. He plugged it into his computer, replacing his two 4870ís, re-installed the relevant drivers, and ran for a full day without encountering any issues at all Ė doing everything from playing games, browsing the internet, and watching videos.
Thinking that I had maybe plugged it into my motherboard incorrectly, I put it back into my computer again. The same problem of constant crashing ensued. Iím completely stumped as to why one of the graphics cards works fine (and still does) while the other, which is theoretically identical and works flawlessly in my brotherís computer, causes constant crashes in mine.
Hereís a list of things Iíve done to try and to fix the problem since it first arose:
- Uninstalled and reinstalled the cardís drivers numerous times, including running Driver Cleaner Pro in between (in safe mode), and returning the AMD control centre to factory defaults (by clicking preferences -> Restore Factory Defaults). I have been using the 11-11 win7 64 bit drivers, which are the most up to date.
- Updated my BIOS to the latest non-beta version, and reinstalled the latest chipset drivers for my motherboard.
- Tried connecting the card to different power supply cables, and connecting my monitor to a different port in the card.
- Iíve also watched the temperature meter within the AMD control centre, which has shown no signs of overheating.
Here are my computer specs Ė
Graphics card Ė PowerColor Radeon HD 6870
Motherboard Ė Gigabyte 990FXA Ė UD3 (bios is at version F5). (<2 months old)
Processor Ė AMD Phenom II X4 955
Power supply Ė CoolerMaster GX 750W (just installed)
OS: Windows 7 64 bit
Iíve hit a dead end and really donít know what else to try. Does anyone know what my problem could be? Any help would be very much appreciated!
Thanks for taking the time to read my (probably excessively) long post.