CPU running Hot - How can Portage help?

SpiderPigLoki · n00b Joined: 22 Aug 2008 Posts: 45

Hey Forum.
Please escuse the cryptic title above, I'll explain that later.

My problem is, that my CPU gets ULTRA hot if I compile something heavy (e.g. Thunderbird, Firefox, Libreoffice). To be exact it only occured with these three so far.

smartass · Posted: Sat Feb 25, 2012 8:02 pm Post subject:

Compiling code is always CPU intensive, not much you can about that.

However, you may be surprised, but Portage can actually help you

Look into the make.conf (5) manpage, and get to know the PORTAGE_NICENESS and possibly (if your HDD gets very warm too) PORTAGE_IONICE_COMMAND variables.

If you aren't familiar with niceness on *NIX systems, read the nice (1) manpage.

Note that setting these variables in /etc/make.conf will make compiling take longer, but will not put such direct load on your system.

BTW, I let my laptop compile with a book under its edge to make more space under the fan vents and set my PORTAGE_NICENESS=15 and my internal temp does not go beyond 65 C

Hu · Watchman Joined: 06 Mar 2007 Posts: 7610

Adjusting the niceness does not necessarily make the build run any cooler. A niced build will more readily defer to other tasks on the system, so the system remains responsive. However, if you have made no other changes, then given the choice between running a nice task or sitting idle, the kernel will choose to run the nice task. Some CPU governors can be configured to treat nice processes as equivalent to idle, in which case a niced build will not bring the CPU up to a higher clock speed. You may also be able to reduce the temperature by using the CPU governor powersave, which locks the CPU to its minimum supported clock speed. This will slow down the compilation, possibly substantially, but it can reduce heat generation.

By far, your best bet is to stop compiling large packages on a system with inadequate cooling. Improve your cooling or switch to a distributed build so that the laptop just installs prebuilt packages.

NeddySeagoon · Posted: Sat Feb 25, 2012 10:24 pm Post subject:

SpiderPigLoki,

First, why do you think the reported temps are correct?
Its very easy to set up lm-sensors for the wrong scale factor and or the wrong sensror type.

Get your CPU nice and warm, then reboot and check the CPU temps in the BIOS. They will be lower, even if lm-sensors is correct as the CPU will cool during the reboot process.

Is this a home made system or assembled by a well known source?

Running hot in home made systems is typically caused by no/too much heatsink compound.
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SpiderPigLoki · n00b Joined: 22 Aug 2008 Posts: 45

NeddySeagoon · Posted: Sat Feb 25, 2012 10:37 pm Post subject:

SpiderPigLoki,

Laptop designs make serious compromises in the cooling department.

When you are building things prop the laptop edges up on two thick books to allow air to circulate underneath.
It that looks ugly, you can invest a substantial sum of money in a 'laptop cooler'.

Depending on the airflow path, standing the laptop on edhe may be better, if that allows used cooling air to exit at the 'top'
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Naib · Posted: Sat Feb 25, 2012 11:38 pm Post subject:

Those 3 are 3 of the biggest packages in the tree with enough bloat in them to take a long time to compile resulting in no real pause during the process (to allow some period to cool).

those 3 packages are available in -bin format as well. It may be worth considering using the -bin variants. But yes duing cpu intensive work will result in increased cpu temperature
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Genone · Posted: Fri Mar 02, 2012 3:14 pm Post subject:

Obvious options would include lowering the numbers for the jobs parameter of both make and emerge, and/or add a load parameter to make as well.

EatMeerkats · Apprentice Joined: 15 Mar 2006 Posts: 234

I wouldn't even worry about it… I'm also using an X220, and modern CPUs are smart enough to perform thermal throttling when they get too hot. I don't have any CPU temp monitors installed, but I'm compiling Wine right now and can see using http://lxr.free-electrons.com/source/tools/power/x86/turbostat/turbostat.c that even though my scaling governor is set to "performance", the CPU is running slower than normal:

thumper · Guru Joined: 06 Dec 2002 Posts: 406 Location: Venice FL

I had a similar problem, it's that time of the year when I have to vacuum out the machine but I won't get to it for another week.

It does have filters but there is work to be done to close the leaks, but thats another topic.

My thermal alarm was going off during some emerges, I have a quad core Phenom II 3.4GHz, making these changes was enough to keep it from hitting critical temps.

SpiderPigLoki · n00b Joined: 22 Aug 2008 Posts: 45

Thank you guys so far.

I will try the new make.conf right now....

sligo · n00b Joined: 17 Oct 2011 Posts: 39

Just came across this thread and wanted to add how i fixed this problem for me.

Having a Thinkpad X61, i always had a heat problem while compiling or running cpu intensive tasks. I've cleaned the fan a couple of times and even bought a new one once. Usually i'm having tpfand running to have a better control over the fan. This way i can have it running at the maximum speed (disengaged mode). Still i was having the problem of getting over 85°C CPU temps crashing my computer, especially in summer times.

The first thing i've tried was cpufreqd. You can set it up to clock up and down the cpu if it gets to hot. Sadly the configuration won't let you finetune much or i might have done it wrong. I was never happy with it.

Later i've choose to manually clock the CPU up and down with cpufreq-set. This works very well but you'll have to do it manualy.

In the end i decided to hack some script to read the temps and tune the CPU to it the way i need it. I am not to much into coding C or else, so its just a short bash script. I run the script from Cron every minute. The Script then runs itself every 2 seconds for a minute. While running it checks the current CPU temp and clocks up or down as defined.