I have 4 5850's and they were all running at around 400 mh/s. However 1 of my cards (device 1) has started producing poor results. It now only runs at 150 - 200 MH/s but will start at 400 MH/s for a few seconds. At least once a day this card will also fail with the hardware verficiation failed error and i then have to restart the minner.
I am using poclbm GPU miner with -v -w 128 settings.
As i said my other 3 cards are fine. Temps are the same for all cards.
I am using the very latest afterburner and running win7 64 bit.
I have reset the overclock back to factory setting and this has made no difference. all 4 cards were running at 900mhz with 600mhz memory.
Does anyone have any thoughts on what is going on as i am at a loss given that all the cards are the same and using the same software and drivers.
There is a strong possibility it's overheating. What are the temps of all your cards?