Freeze/SICK/DEAD/511 issue on 3x7850

[Muffnz]

Hi all. I have mini mine rig 3x7850 Sapphire 2gb. I use cgminer 3.7.2, 13.12 AMD Drivers, SDK 2.9. Motherboard - Gigabyte 780T-D3L and 6gb RAM.
After 5-30 min start cgminer my rig freeze. Yesterday i have SICK/DEAD and 511 temp error on one(only one) card. But yesterday i have 13.4 drivers, today i install 13.12 and no more SICK/DEAD/511. Just only freeze, and only reboot rig can fix that.
What can i do? I have this config for all card. 330 KH/s for one. But when i start use this rig in decembr, i have 369 Kh/s(gpu on 1075 mem on 1215)
cgminer.exe --scrypt -d 1,2,3 -w 256 --thread-concurrency 8192 -I 18 --auto-fan --temp-target 65 --gpu-engine 1025 --gpu-memclock 1185
What can i do?

[lapepite]

i have the same problem , rig run still 3month without problem, now if i try one gpu per one it's good but both gnu i get sick and freeze...
i didn't find any solution on internet..

thank you for anybody can help..