Scott Silva wrote:
> on 6-4-2009 5:37 AM Theo Band spake the following:
>
>> I have a quad core CPU running Centos5.
>>
>> When I use top, I see that running processes use 245% instead of 100%.
>> If I use gkrellm, I just see one core being used 100%.
>>
>>
> This one is easy. 4 cpu's, 100% total each, a maximum of 400%.
>
> Since one core is at 100%, the other 145% is spread across the other 3 cores.
>
Not quite. If I run 4 processes (4 times cpuburn-in) I see this:
Cpu(s): 50.2%us, 0.9%sy, 48.9%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si,
0.0%st
14696 thba 25 0 2064 984 1080 308 R 244.9 0.0 0:40.57
cpuburn-in
14695 thba 25 0 2064 984 1080 308 R 243.2 0.0 0:43.21
cpuburn-in
14698 thba 25 0 2064 984 1080 308 R 242.9 0.0 0:34.47
cpuburn-in
14697 thba 25 0 2068 988 1080 308 R 162.0 0.0 0:25.86
cpuburn-in
14402 made 31 15 117m 24m 93m 11m R 40.9 0.4 1:11.56
eldo_64.exe
13746 kedo 39 15 696m 611m 85m 23m R 40.3 10.3 34:29.50
common_shell_ex
So in total 100% (first line) and counting the process %
(244.9+243.2+242.9+162.0+40.9+40.3=974%). One of the cores runs three
processes also totaling up to (162+40.9+40.3)=243%
To me it looks like all values are just multiplied by 2.43 (400%x2.43=972%)
I did disable hyperthreading in the bios. The machine would otherwise
show up with 8 CPU. Hyperthreading does benefit my application.
Theo
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