Hi diablod3 I am facing some issues using this miner with dual 6990. With -f 1 the hash rates drop to a whooping 600000 low. I tested out different flags and found that -f 17 to 20 is the best with the highest at 1ghash/s. This is very stable compared to poclbm which fluctuates from 800mhash to 1.2ghash. I am using 11.3 + 2.4 sdk like u recommend. The preview 11.4 drivers + 2.4 sdk yield the same results. I am using windows 7 64 bit. And the only way to get the software to recognise the dual 6990 is to crossfire them. Any advice u could give me?
Thank you =)
On Windows, due to stupidity on Microsoft's part, you usually need a dummy plug to make cards that don't have monitors plugged in to them turn on (this doesnt apply to Linux, nor Crossfired cards). -f controls the length of a kernel (1/n seconds, where -f 1 is a full second), and you'll only see changes at large multiples or divisors of 60 (ie, 1, 15, 30, 60, 120, 240, etc).
-f 1 tends to largely skew the realtime clock used by the OS. So, to test with -f 1, you need to run for about 10 minutes and only rely on the second number (pocblm does not provide a second number, so you can't accurately watch it).
That said, the numbers tell me you should get about 1.2 ghash total instead of 1 (or about 17% slower). I suspect a driver bug. Make absolutely sure you've turned off Crossfire and that my miner lists 4 devices.