Author

Topic: 2nd GPU = 14% CPU usage (Read 2116 times)

full member
Activity: 154
Merit: 100
July 28, 2011, 09:50:46 PM
#10
i have started a thread at amd dev forum - opencl section about the 100% cpu usage bug with >1 gpu installed. feel free to jump over there and post your support for this issue being addressed...

http://forums.amd.com/devforum/messageview.cfm?catid=390&threadid=153211&enterthread=y
full member
Activity: 168
Merit: 100
May 13, 2011, 05:42:05 AM
#9
Anyone have any ideas?  I hate that it was working with 2 GPU's mining with 14% CPU load now its like 26% Sad
full member
Activity: 168
Merit: 100
May 12, 2011, 05:41:22 AM
#8
Strange its now using 27%  Huh

I'm 100% sure I had both GPU's running and was only using 14% earlier today.

I did start and stop phoenix several times, but still thats strange.

Any clues?
full member
Activity: 168
Merit: 100
May 12, 2011, 12:50:09 AM
#7
Can't do linux for my main system, but maybe for future builds.

Also for a dedicated system, I suppose you could disable some cores and underclock it to save on power?  Or do you think this would hurt the GPU performance?
newbie
Activity: 17
Merit: 0
May 11, 2011, 07:32:29 PM
#6
Consider yourself lucky as I get 50% cpu usage with both my 6950 and 5850 mining. The best I can get is 25% usage by limiting the affinity to only 1 core for both miners.

I've heard linux doesn't have this problem though so you could try that.
member
Activity: 98
Merit: 10
Testing
May 11, 2011, 07:24:05 PM
#5
it just makes the cpu 100%, or as your Core i7 has 8 threads, it will max out one thread per GPU instance when using multiple GPU

I have a dual core Athlon II 3.1Ghz with 4 GPU. The CPU is at 100%, all GPU still run max Mh/s Smiley
full member
Activity: 168
Merit: 100
May 11, 2011, 06:16:20 PM
#4
What about a 3rd or 4th GPU.  Will it go up another 14% and another 14% again???

How about if I had 3 GPU's on a Singl core Sempron 140, what would my CPU load be like?
hero member
Activity: 699
Merit: 500
Your Minion
May 11, 2011, 05:17:39 PM
#3
Agreed, it's the nature of the beast.
Dual 5850's do the same here on i7 regardless of cpu speed.
legendary
Activity: 1400
Merit: 1005
May 11, 2011, 04:37:24 PM
#2
You can't.

It's the nature of multi-GPU mining - it'll max out at least one core.  No fix for it yet.
full member
Activity: 168
Merit: 100
May 11, 2011, 04:34:35 PM
#1
I just started mining last week.

I added a 2nd 5830 to my rig.

Before CPU usage was 1% on my Core i7 930.

With the 2nd GPU, my CPU is @ 14% usage when mining and when the 2nd instance of Phoenix 1.4 is open.

What should I do to get CPU usage down?

I'm on Win7 64bit.

Thanks!
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