DRAM failure rates
This is interesting, especially since the MS paper "Cycles, Cells and Platters" ( http://research.microsoft.com/apps/pubs/default.aspx?id=144888 ) provides evidence that overclocked machines are significantly more likely to show memory or HDD failures. Yes, you will get performance, but you'd better use higher end ECC memory (chip-kill/chip-spare) and plan for failures, as well as having an OS that is ready to handle the memory check reporting that comes with the Nehalem-EX architecture -the one lets the OS blacklist memory pages that are playing up.