Flutterby™! : Microsoft looks at hardware faults

Extreme Tech: Microsoft analyzes over a million PC failures, results shatter enthusiast myths.

The Microsoft Report: Cycles, Cells and Platters: An Empirical Analysis of Hardware Failures on a Million Consumer PCs:

... Among our many results, we find that CPU fault rates are correlated with the number of cycles executed, underclocked machines are significantly more reliable than machines running at their rated speed, and laptops are more reliable than desktops.