Running CGminer and CPUminer at the same time - performance issues

[Nullu]

I'm running an optimised version of CPUminer, but it's absolutely killing my hashrate in CGminer on my R9 280x. Cudaminer doesn't seem affected at all by it, but even using just one thread makes my hashrate drop in CGminer.

Does anyone know a way around this? I have an overclocked CPU I'd like to take advantage of, but it's really affecting my hashrate on my AMD card.

[Wipeout2097]

Set CPUMiner to idle priority and use 1 less threads than the ones your CPU has. Put cgminer in realtime priority

In a batch file, use for example if your CPU has 8 threads

"start /low /affinity 7f minerd.exe ..."
"start /realtime cgminer.exe --config ..."

That 7f is a mask in hexadecimal (=01111111 binary) that prevents the cpu miner to use the last thread, leaving it free for cgminer and windows

[Nullu]

Thanks for the advice, it's really useful. I'm getting about 600khash now on average, compared to 550khash before.

It seems to settle around 600+, then after a few minutes drops to about 550. I might try using 2 cores instead of 3 and see if that helps.

Edit: Ok, using 2 cores did the trick. I'm now mining at pretty much the same speed I was before. Now I can mine my on my overclocked i5, GTX 670 and R9 280x at the same time.

Thanks for your help. 

[Wipeout2097]

np. Your hashrate is still very low though

[Nullu]

np. Your hashrate is still very low though

It's a throttling issue. If I stop running my GTX670 the hashrate will go back up. I think it's a heat issue rather than anything else. I'll have to get an open air case or build something better.