Hi all!
So. First card I have to give up upon. I usually manage to get decent values that are in the upper ranges of what can be achieved with my other cards (7790, 7770 and 7750) whilst mining scrypt.
So. This is a 100% fresh install Win7 on E5200 c2d, powersupply is a high quality 520w Corsair 80+.
I have tried two other cards in this system and they worked flawlessly and with high performance.
At first replacement with the Sapphire 7970 (SAPPHIRE HD 7970 3GB GDDR5 (21197-00)) I managed to get 560kh/sec with the standard, optimal settings:
-I 13 -g 2 -w 256 --thread-concurrency 8192 --gpu-powertune 19
Driver : ATI 13.9, stock bios.
I found this to be quite low, so I tried fiddling with settings. Nothing seemed to work, so I flashed improved/recommended 3072.1.20926 bios.
This made results worse - I was stuck at 420kh/sec now.
I flashed back to original bios. With identical settings as before I got 560kh/sec again. I flashed a different bios that was recommended. 420kh again...
Unfortunately after flashing back to stock bios, rates were stuck at 420kh/sec (99% gpu usage).
Tried every clock speed between stock and 1080/1550 (mild improvement in kh/sec but nothing major)
Tried 0-20 powertune.
Tried under/overvolting.
Tried fanspeed @ 100% and opening window (temps <65c)
Tried installing 13.9, 13.11, 13.10 drivers (with and without driver sweeper in between)
Finally I gave up. I tried some more settings and found out that setting gpu to 1 instead of 2 threads at least gave me 519kh/sec @ 94% gpu util.
I really don't know what to do. I even flashed MSI bios that gave no better performance. It's like this card is bewitched..
If anyone wants to help out - I'd be happy to accept. Teamviewer access is possible.