Geek warning!!!

This weekend, I decided to give an honest attempt to see how much I could 
overclock my new cpu.  For reference, the core i7-860 stock speed is 2.8GHz.

Long story short, I was able to hit speeds of 4.4GHz and it would still 
post, but at that point, I had the voltage set as high as it Intel says to 
go (1.4V) and it would have run so hot under load that there was no way it 
could be useful, so it was more of a "Let's see how high I can go!" setup.

Ok, before I go further, I'll have to explain a bit.  The 4.4GHz was really 
a 4.2GHz overclock with "turbo boost" or whatever the heck it's called. 
Apparently, the OS can change the clock speed dynamically, alternating 
between a multiplier of 9 and 22.  The 860 is normally set at 21.  At lower 
speeds, I actually ran some tests and with a simple POV-Ray scene (low 
memory usage), there was no difference between running at, say, 4GHz with 
turbo boost turned off (21x mult), and 4GHz (22x mult, 3.8GHz with 21x mult) 
with turbo boost on.  i.e. 4GHz is 4GHz regardless of how you got there.

I was able to achieve 4.2GHz, but heat became a serious problem.  I was 
using Prime95, and temps were approaching 80C.  I turned away for a couple 
minutes, then Prime95 started the next test and YIKES!  Temps were in the 
mid-80's.  STOP! STOP!  You're not supposed to take the chip above 78C 
according to what I've read.  But it otherwise seemed stable.  I tried a 
more powerful CPU fan, but it didn't seem to make any difference.  I think 
you can only conduct so much heat.  At some point, I think it doesn't matter 
how big the fan is.  I ran my POV-Ray benchmark (not The Benchmark) scene at 
3:55.  That was the lowest I ever saw.  Any higher speeds would crash 
Windows.

Ok, so I tried 4GHz.  Still too hot.  Core temps would occasionally spike 
into the low 80's under full load and that's just not cool (pun intended). 
So more tweeking and lowering voltages, and I found that 3.88GHz (incl. 
turbo boost) seemed to be the highest stable speed I could get.  I ran 
Prime95 with maximum heat stress, and it would run (core temp) 75-76C. 
That's pretty warm, but still under the reference limit of 78C.  I ran 
Prime95 for over 4 hours while occasionally playing Quake 3 and solitaire 
too, and it worked well.  My POV-Ray benchmark ran at 4:20 and temps never 
went above 70C.

Ok, 76C core temp may not actually be 76C.  One of the cores, Core #0, seems 
to run as much as 5C hotter than the rest at all times.  Apparently, that's 
normal, and some have speculated that it's Intel's way of scaring people out 
of overclocking to high, or perhaps to cause a thermal shutdown. 
Regardless, if Core #0 hit a max of 76C, the other cores were between 71C 
and 73C.  Idle temps were always 20's and 30's, which is really cool.

Summary:  4.4GHz would post, but couldn't load Windows.  4.2GHz might have 
been stable, but way too hot.  4GHz seemed stable but still too hot. 
3.88GHz, stable, and warm.  3.5GHz very cool, very stable.

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