Dual core: symmetric or asymmetric cpus load?

[gentunian]

hey there,

i've been watching the cpus monitors in my box. I use the fantastik-ng-dual-core theme of superkaramba. The monitor shows the activity of both cpus. I have taken screenshots but i dont have any site to upload and show you the average load of both cpus. The thing is that both cpus has an asymmetric (or symmetric depending the point of view) load. I mean: When a cpu load is 100% the other is 0%, or when cpu1 is 50% the other is 50% and so on...So, if you see the graphic is some kind of "symmetric" reversed graphic (i explain myself?).

But, when i do an emerge (generally i do this in the console's, alt+f1, ...f2, etc) i use top to see the cpu load, and it doesnt seem to be so "asymmetric" (let explain myself: i mean symmetric because the draws of lines like there were mirrored, and asymmetric it's the same thing but not graphical. So a symmetric draw, its a kind of asymmetric load...understand? I would explain better in spanish, sorry for that. Symmetric load means that they load in nearly the same percentage. Symmetric lines means mirrored lines, so the load its reversed...well, that was my effort).

Conclusion: Compiling (emerging) the top shows up that the two cpus are working really in parallel. Doing some other thing (copying, moving, etc) the load its asymmetric. It's this okey? what do you think?

Well, i must say that my english, as you maybe already know, its not quit good as a native english speaker, so i'm sorry for that.

Regards,
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[Suicidal]

I have noticed that as well on some applications; my only thinking is that some applications do not take advantage of dual CPU's very well.

[DirtyHairy]

The only way to benefit from multiple processors is to run several task in parallel. Therefore, the only applications that benefit directly from dual core CPUs are those that launch multiple threads, which many programs don't. You still benefit from your core duo though, since a single thread will use up at most one CPU, and so the system will perform better under load...

[bunder]

nothing wrong with apps that won't run in multithread... having apps run exclusively on certain cpus can actually be a benefit in some cases. if this is for you, read up on cpusets and download "bunhax".

https://forums.gentoo.org/viewtopic-t-492108.html

cheers

(the default scheduler bounces apps between the cpus to give an even system response. i don't prefer this type of scheduling routine... i'd rather set the affinity myself via bunhax)
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