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algetards 09-08-2013 05:30 PM

Manually allocating processor core usage?
 
Hi all,

So I'm not sure if I'm posting this in the right seciton, but here it goes. So my logic board is broken and Activity Moniter shows that kernel_task (the os itself) is using between 500-600% CPU usage (I have 8 cores so this is about 63-75% CPU capacity)

For reasons I won't get into, I can't fix my computer for about a month. However, there are some higher-performance things I still would like to do. For example, play Dwarf Fortress. Now Dwarf Fortress is not multithreaded, so in theory, if the crazy-high kernel_task usage is restricted to 6 cores, and I can somehow guarentee that 1 core is mostly dedicated to Dwarf Fortress, then I could still play it to a degree. (It's possible that slowdown due thrashing and multi-core issues makes this impossible, but I'm not sure).

Is there some way I can run the program giving it precedence to one of the cores? Or on the other side, restrict kernel_task to the first 6 cores? I'm pretty sure the program itself has no mechanism for this, so it would have to be something from the mac side. I thought maybe virtualizing a machine and dedicating the cores to that machine might work, but the overhead might make the whole thing slower. I'm a technical user, so any suggestions are welcome.

Thanks,
Sam

Lifeisabeach 09-09-2013 09:38 PM

Quote:

Originally Posted by algetards (Post 1535851)
So I'm not sure if I'm posting this in the right seciton, but here it goes. So my logic board is broken and Activity Moniter shows that kernel_task (the os itself) is using between 500-600% CPU usage (I have 8 cores so this is about 63-75% CPU capacity)

What the.... ???? I'm dying to now exactly in what way your logic board is broken; why that is making the OS use the CPU to that degree; and how you plan to fix it. Seriously. I don't even know how this thing is running.

Quote:

For reasons I won't get into, I can't fix my computer for about a month. However, there are some higher-performance things I still would like to do. For example, play Dwarf Fortress. Now Dwarf Fortress is not multithreaded, so in theory, if the crazy-high kernel_task usage is restricted to 6 cores, and I can somehow guarentee that 1 core is mostly dedicated to Dwarf Fortress, then I could still play it to a degree. (It's possible that slowdown due thrashing and multi-core issues makes this impossible, but I'm not sure).

Is there some way I can run the program giving it precedence to one of the cores? Or on the other side, restrict kernel_task to the first 6 cores? I'm pretty sure the program itself has no mechanism for this, so it would have to be something from the mac side. I thought maybe virtualizing a machine and dedicating the cores to that machine might work, but the overhead might make the whole thing slower. I'm a technical user, so any suggestions are welcome.
Someone more knowledgable may come along to contradict me, but from what I understand, an app can only use multiple cores if it knows how to. Besides, if the OS is really using that much CPU power on its own, I would venture that trying to do anything more that's CPU intensive would be very... very... foolish. You are just begging for this thing to overheat and kill the CPU.

vansmith 09-09-2013 09:49 PM

I think you need to solve the excessive kernel functioning rather than containing the problem.

The kernel will frequently use quite a bit of memory but unless you're doing a lot of low level stuff, the kernel doesn't/shouldn't be blowing through CPU cycles like that. What are you doing on that machine?

pigoo3 09-09-2013 10:19 PM

Quote:

Originally Posted by algetards (Post 1535851)
So I'm not sure if I'm posting this in the right seciton, but here it goes. So my logic board is broken and Activity Moniter shows that kernel_task (the os itself) is using between 500-600% CPU usage (I have 8 cores so this is about 63-75% CPU capacity)

If your logic board was truly broken...there's a strong possibility that the computer wouldn't even work.

Try this:

- Open Activity Monitor
- near the top of the Activity Monitor window choose "All Process's" from the drop down menu.
- look thru the list to see what's using all of the "% CPU" resources.
- then select the "offending" activity
- then click on the "Quit Process" icon.

See if this helps. If not...try booting the computer from an external hard drive with a fresh install (and a fresh install only) of the OS version you're currently running. See if this helps.

If the external HD idea helps...then you have applications that are running on your computers internal HD that are using up the cpu resources.

- Nick

vansmith 09-09-2013 11:22 PM

Can you (force) quit the kernel_task process? It seems like that could be dangerous.

pigoo3 09-09-2013 11:43 PM

Hey what the heck...the guy's already got an 8 core computer using 500-600% cpu unnecessarily.;)

I kind of prefer the "fresh OS install on an external HD" idea myself. If the internal HD has a problem that is software related...even if the kernel task is the issue & can be "quit" via Activity Monitor...the problem will only return on rebooting.

Basically if none of these ideas work...then maybe there is a hardware issue.

I always fall back on the issue I had with the core 2 duo MacBook Pro that my wife is now using. It had an almost 200% cpu issue (max. cpu use for a core 2 duo computer)...I tried everything I suggested in this tread & more with no solution.

Took it to the Apple Store (still had warranty on it)...they said that it was a bad fan. Fan was replaced...computer has been great for over a year!:)

- Nick

pigoo3 09-09-2013 11:51 PM

Actually I just tried quitting the kernel task on my computer (putting my money where my mouth is so to speak);)...and Activity Monitor does not allow it (the "Quit Task" button doesn't activate).

When I mentioned quitting a task in Activity Monitor in my 1st post above...I was really thinking of other tasks. The I reread the OP's post...and saw that they actually mentioned the kernel task as the problem.

So maybe the external HD idea (or booting into Safe Mode) are better things to try.:)

- Nick


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