Computer gets really hot under Linux

When I'm in Linux, even just idling, I can hear the fans of my Pentium 4 (yes, it's a shitty processor, but that isn't the point) working overtime to where they sound like a vacuum.

The only time it does this in Windows is when I have Oblivion or SimCity 4 running for about an hour.

I even have my Linux kernel dynamically-throttle my CPU speed such that Linux only turns up the frequency when a program is running that needs more computing power (I believe this is the CPUFreq series of settings in the kernel setup), and even when the cpufreq is a mere 400mhz, the fans are spinning as if the CPU is going at full 3.2ghz.

What can I do to prevent Linux from making my computer into a sauna-creation machine all the time?

In before "delete Linux and your shitty Pentium 4"

It's a problem with some process constantly waking the kernel. Unless you know how to find which process is causing this, I'm not sure how you can fix this problem yourself. There is work being done to make Linux and some programs less demanding so maybe the problem is fixed in the future.

wow, linux sounds great...

Um, no. It sounds like a problem with a particular set up. Nothing more.

1. Make sure that the CPU is actually clocked down by linux. What facility do you use to achieve this?

One of the in-kernel governors? From your description it sounds like you are trying to use the "conservative" governor. If so, did you make the appropriate entry in your config files so the correct one gets used?

If not, what else are you trying to use? A daemon that dynamically changes the frequency? if so, Did you configure and start it correctly? Did you remember to compile the "userspace" governor into the kernel and configure it correctly?

Watch the CPU frequency for some time as you work. Does the dynamic frequency changing seem to work?
# watch grep \"cpu MHz\" /proc/cpuinfo


2. Your fans running on a high setting all the time might indicate a problem with ACPI in general. Look through your kernel's ACPI config and read a few howtos to compare. Look through dmesg and your logs to see if there's an indication of the kernel having trouble with your BIOS's implementation of ACPI. A number of BIOSes have faulty/buggy implementations. Determine your mainboard/chipset/BIOS model and versions and lookp up on the internet if there's a known problem with ACPI. Sometimes you can find fixed ACPI tables that you can use instead.

You can use lm-sensors to monitor temperatures and set fan speeds.

Or look through your BIOS for fan settings. If you have an ASUS BIOS, check whether the Q-Fan feature is enabled.

>>1
look for a zalman pc fan for your motherboard and get some artic cooling thermal greese, and volla

>>5
>>One of the in-kernel governors? From your description it sounds like you are trying to use the "conservative" governor. If so, did you make the appropriate entry in your config files so the correct one gets used?

Nope, I don't even have that governor available, according to sysfx:

root@longcat:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_available_governors
ondemand powersave userspace performance

root@longcat:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_available_frequencies
400000 800000 1200000 1600000 2000000 2400000 2800000 3200000

root@eutow:/sys/devices/system/cpu/cpu0/cpufreq# cat cpuinfo_cur_freq
800000

(I have 800000 set to the Minimum, not 400000)

So right now it's at 800mhz and yet the fans are going into full-throttle mode.  Again, in Windows this only happens when I've been playing Oblivion for an hour or two.

>>If not, what else are you trying to use? A daemon that dynamically changes the frequency? if so, Did you configure and start it correctly? Did you remember to compile the "userspace" governor into the kernel and configure it correctly?

Nope, no daemon.  Just using sysfs to set the minimum, the maximum, and the governor -- the kernel takes care of the rest.

root@eutow:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_governor
ondemand

So ondemand is the governor.  It's been forever since I configured Linux like this; there was a good reason I went with ondemand instead of the other available governors, but I forgot the reason (and also forgot what the differences were in the governors).

>>2. Your fans running on a high setting all the time might indicate a problem with ACPI in general. Look through your kernel's ACPI config and read a few howtos to compare. Look through dmesg and your logs to see if there's an indication of the kernel having trouble with your BIOS's implementation of ACPI. A number of BIOSes have faulty/buggy implementations. Determine your mainboard/chipset/BIOS model and versions and lookp up on the internet if there's a known problem with ACPI. Sometimes you can find fixed ACPI tables that you can use instead.

I will do this.  This is a piece of shit Dell, after all.  I'm definitely building my own computer from scratch using carefully chosen parts the next time I need a new one.

>>6
>>You can use lm-sensors to monitor temperatures and set fan speeds.

Again, this is a piece of shit Dell -- I wasn't able to get lm-sensors working.  I don't think Dell's motherboard has temperature reporting capabilities, from what I've tried.

And yes, my computer isn't really named longcat.  I was trying to be "cute" at first, because I'm an enormous 4chan faggot, and then forgot to type-in 'longcat' in my hostname when I pasted the other lines.

Sorry, but I could only find info on FreeBSD.
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/funnies.html#VERY-VERY-COOL

I found out it IS related to ACPI; despite fan controls for ACPI being compiled in, the /proc/acpi/fan (I think) subdirectory somewhere was empty.

Funny -- I am now in SystemRescueCD, a LiveCD linux, and the fans are being normal.  ACPI is not compiled in at all, and SysRescCD's kernel (2.6.22) is later than the kernel I use for my "live" Linux installation (2.6.20).  So maybe my solution should just be to remove ACPI support from my kernel.  It's not like I ever use Sleep/Hibernate features.

Yes, the problem is that linux follows ACPI specs very striclty, which Windows does not. And a number of BIOSes don't either and are thus technically flawed. Now if you boot a linux kernel on one of those BIOSes, many strange things can happen.

You can try updating your BIOS or get fixed ACPI tables for the time being. And with a little luck, a workaround for your board/bios may get put into the kernel in some time.

>>12 here
Forgot: Of course, you can also leave ACPI out for the time being, if you can live without suspend, frequency scaling etc.

Is your machine really called ``longcat''? That's so cool!