Topic: Monitor freeze & Reboot with stock frequencies (Read 530 times)

Hi,

I just bought quite many Sapphire HD 7950 With Boost, GPU's and I'm having a lot of trouble having them being stable.
My system is the following:

MB: Asus P8z68-v Gen3
8GB RAM
Intel i5-3570k
2x mentioned GPU's
PSU: 1050w Seasonic Gold

So I'm using stock voltages and clock speeds for both of the GPU's just to try to keep it stable at first. The problem is that after 5-30 minutes my monitor freezes and after a while system reboots. I'm using Windows 7 Professional, AMD Catalyst 13.11 Beta 4 drivers, latest AMD SDK and CGminer 3.7.2. I know it can't be the PSU since it should have a fairly enough power for both of these cards.

Some parameters for CGminer: -I 20 --thread-concurrency 24000 --shaders (or similar) 1792 --gpu-memclock 1250 --gpu-core 925

I'm running out of ideas that what could go wrong? GPU temperatures are around 60-70.

Earlier I had 1x 5870 and 1x 7950 configured on the same motherboard, heavily overclocked and it was working perfectly without problems. And I noticed that the more I overclock these new cards the shorter it takes for monitor to freeze. I have also tried with 3x of these new GPU's and it's the same problem so I moved to 2x which both are on pcie 16x.

So basically, could this be a driver issue, should I lower the intensity (Everyone else with this card seems to be happy with 20), temperatures can't be too high, should I try with linux...Any advice would be really appreciated. Thanks all!