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High System CPU Usage with Bulldozer Processor

Asked by Michael Murphy

I'm noticing that with the Bulldozer processor (Im currently using Phenom FX 8120) and the Sabertooth 990FX with 810 Beta BIOS, I have high system CPU usage. I am seeing this with top while using Folding@Home. While System usage is only around 2-5 percent with my Phenom II X6 machine, CPU system usage is around 50 percent.

What I mean by system usage is that on top it demonstrates (percent)sy as 50 percent. Then the remaining portion is percent nice which is what the user sees. In other words, why is it that on Bulldozer I am getting only 50 percent of the processor for actual programs while with Phenom II I get the entire processor? I note that this may be the reason as well for the bulldozer being slow in benchmarks compared to Phenom II processors. It seems that this processor is capable of 2x the speed of Phenom II X6, yet 50 percent of system usage is being eaten for an unknown reason. There is a lack of information on the Internet, and I would like to confirm that this also happens on other systems with Bulldozer processor with different BIOS/motherboards.

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delance (olivier-delance) said : 		#1

Could you convert question into a bug ?
By curiosity, could you paste here the result of "top" command for both processor when PC is idle ?
In both case, do you have an integrated GPU chipset ?

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Michael Murphy (mmstick) said : 		#2

Tasks: 244 total, 1 running, 236 sleeping, 7 stopped, 0 zombie
Cpu(s): 0.1%us, 0.1%sy, 0.0%ni, 99.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 16430528k total, 10660864k used, 5769664k free, 1567700k buffers
Swap: 15624996k total, 0k used, 15624996k free, 6672332k cac

This is what the system shows when idle on FX-8120. And the Phenom II X6 machine shows the same with 0.1-0.4%sy usage.
Running World Community Grid on all 6 cores on X6 and 8 cores on FX-8120 shows 0.4%sy usage which leads me to believe it is an issue with inefficiency in Folding@Home.

Also, the FX-8120 has a dedicated GPU while Phenom II X6 has integrated.

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