Hi guys,

I have some new rig 470/480/570/580 (about 10). Some of them are working great and stable, others not.

GPU0 t=77C fan=80%, GPU1 t=76C fan=79%, GPU2 t=81C fan=79%, GPU3 t=69C fan=78%, GPU4 t=69C fan=79%, GPU5 t=78C fan=78%
ETH: 10/10/17-11:10:50 - New job from exp.epool.xyz:3333
ETH - Total Speed: 148.773 Mh/s, Total Shares: 3942, Rejected: 0, Time: 14:26
ETH: GPU0 23.809 Mh/s, GPU1 29.829 Mh/s, GPU2 30.169 Mh/s, GPU3 12.744 Mh/s, GPU4 22.027 Mh/s, GPU5 30.196 Mh/s

As you can see, this is a rig with 6 Rx580 (exactly the same: manufactor, memory type..) with modded bios. GPU 1,2,5 work fine, but GPU 0,3,4 is not, they never reach other's speed (100% gpu usage, the same core/memory clock in GPU-Z) except the begining of mining (when I start the miner, the fist hashrate of them usually great, then drop rapidly after 2 or 3 times showing speed )and I really have no idea about this problems.

This problem also happen with the 470/480/570/580 rig, sometime only 1 low-speed GPU, sometime 3-4 GPUs, with any GPU driver I can get (the original CD driver or the fix dag beta or the newest driver on website), with claymore miner 9.7, 9.7 or 10. These rigs have differrent mainboard, CPU too. Note that all GPU I have tested on my main desktop and got all great hashrate.

After a little bit searching, I found that somebody have similar problem on win10 with very low hashrate (~2-3Mh/s) and solved when install win7, but I dont think it's the root cause so I raise them here to get some discussion (and I dont want to run it on win7 too).

I using win10 64bit, 4GB RAM, ~20GB virtual memory.

Thanks for your help.