Keeping my cool
Keeping computers cool is a problem that's existed for decades, and doesn't appear to be ending any time soon. High-density CPUs and integrated circuits can generate a lot of heat, typically in proportion to the processing load imposed on them. Because the processing load can vary sometimes unpredictably, it's a good idea to have a cooling solution that keeps your computer components cool in all situations.
I've got a Pentium 4 3.0 GHz PC running Fedora Core 6 that I use for remote access to our home network via SSH & VNC. The computer case sits in a coat closet with very little ventilation. This is good for us in that it blocks that computer noise from being heard throughout the apartment. However, it can contribute to an overheating situation depending on the inside temperature and the computer's processing load.
I recently noticed that the internal temperature on the PC was around 130 degrees Fahrenheit. This is within the tolerances of the Intel P4 CPU; however, I'd like to keep the temperature closer to the room temperature for the sake of safety.
So, I went to Fry's an bought an Antec Super Cyclone fan that installs in two card-expansion ports. It has 3 fan speeds (I'll keep mine on High), and effectively moves air from the inside to the outside of the case. Previously, I just had a case fan blowing air around inside the case, but no means of getting that air out.
After completing the hardware work, I then moved on to the software side. I installed the lm_sensors package by running the usual yum install lm_sensors. I then configured lm_sensors by running /usr/bin/sensors-detect and added the recommended lines to my /etc/modules.conf and rc.d files.
After restarting, I was able to see the status of my CPU and fans (but not the new Antec fan, it's not powered off the motherboard). Here's some output from running /usr/sbin/sensors -f:
fan1: 2393 RPM (min = 30681 RPM, div = 4)
CPU Fan: 2596 RPM (min = 2616 RPM, div = 4)
fan3: 0 RPM (min = 66 RPM, div = 128)
M/B Temp: +86°F (high = +16°F, hyst = +55°F) sensor = thermistor
CPU Temp: +97.7°F (high = +176°F, hyst = +167°F) sensor = thermistor
Everything is looking good!