Temperature and reliability

Generally, motherboards are air cooled with heat sinks on the larger chips such as the northbridge and CPU, and they have monitored sockets for case fans. Newer motherboards have integrated temperature sensors to detect motherboard and CPU temperatures, which can be used by the BIOS or Operating system to regulate fan speed. The removal of waste thermal energy became a major concern for workstation PCs around 2000, with the problem becoming more severe over time as computer systems continued to consume more and more power.

A study of the German c't computer magazine c't 2003, vol. 21 pg. 216-221 found that some spurious computer crashes and general reliability issues ranging from screen image distortions to I/O read/write errors can surprisingly be attributed not to software or peripheral hardware but to aging PC motherboards.

Motherboard voltage regulation uses electrolytic capacitors. These capacitors exhibit aging effects which depend on the temperature of the parts, since their water based electrolytes slowly evaporate leading to capacity loss and motherboard malfunctions due to voltage instabilities. While most capacitors are rated for 2000 hours at 105 degrees Celsius, their expected design life roughly doubles for every 10 degrees below this. At 45 degrees a lifetime of 15 years can be expected, which appears reasonable for a computer mainboard. In the past, many manufacturers delivered substandard capacitors, which would reduce this life expectancy figure. With inadequate case cooling this can become a serious problem. It is, however, possible to find and replace broken capacitors on PC mainboards. For more information on certain types of premature capacitor failure on PC motherboards, see capacitor plague.