OC-ing for some is sport; for others it is voodoo; then others with software that they earn their income with it is necessary to get projects done ASAP. I have OC-ed everything from a Radio Shack TRS-80, in the day. There are rumors of failed CPUs, but as gripey as people typically are on the net I have not seen any post made by a real victum. I might come close by turning on systems without the HSF in place. 10 years ago that was no big deal for Intel chips, AMD died instantly ... 1st hand experience with the geeky neck tie clip as a result.
I have 2 I7 systems that are OC-ed as much as possible tuned to my software. These are a i7-920 (@4.3 -ish GHz for ~2 years?) and a i7-990x (@ 4.5 GHz) for the past few months. My numbercrunch software can run for days with alllll of the CPUs bouncing between 70% to 99% during that time and until today in an unairconditioned office. Because of a recent heat wave thru the region I had to back the OCs off a bit. Today serious A/C was finally installed in the house & the OC will get bumped up again.
During the decade(s?) of OC-ing, it has become clear that when things start crashing it is a direct indicator of clogged heatsinks. Somewhere on techgage are pix with some best bad examples of nasty looking collections of dust. And this is in the air you breath!!! And it is perfect sense that as you OC the margin of cooling with the HSF will decrease.
Also, buried in techgage are a few of my own rants about cleaning computers, either naturally aspirated (aka air cooled) or water cooled. The i7s are water cooled for what it is worth to you.
Last, I am only an occasional gamer. No time to do more which is a complaint, a bit of a brag, and a high class problem. The point is, is that video cards are not much of a priority for my computational interests == less $$ investment in video cards. But, I have thought about it, and I would definitely get WC-ed video cards to OC without hesitation if they were a priority.
I have 6 computers of various "power" levels around me. Because of that and the cleaning issue, I am now waiting for this device
to arrive. When it arrives, I'll post a minimal crude review on techgage, but to the elimination of searching for cans of compressed air .... YAAAY!!!