Here's something interesting from Microsoft research. They statistically analyzed automated post-restart crash reports and mini-dumps for a million consumer PC devices for an eight-month period. They found that laptops, in general are more reliable than desktops, having more RAM leads to more crashes (!), and underclocking substantially improves reliability while overclocking unsurprisingly does not. Also big manufacturer boxes are more reliable than white boxes.
Report is here: https://research.microsoft.com/pubs/144888/eurosys84-nightingale.pdf
What they didn't mention that I'm still a little curious about is whether turning on speed-step or whatever it's called on my desktop and my Thinkpad is beneficial. I've watched CPU speed go up and down, up and down continuously on my C2D laptop and AMD quad-core desktop, and I've always suspected that that the speed-regulation process just can't be
very good for it. I keep both set for "Maximum performance" anyway (when plugged in) because I'd rather have all the gitty-yup instantly available.