I got no experience in SB but the best way to increase the lifespan at stock or not is to not increase voltage pass 1.25v AND dont get temps over 65*C but i recommend staying under 65*C... I got no experience on SB so when you OC, just stay near 1.25v and dont go over 60*C... On my i7-950, the stock voltage I saw was 1.27v and it was reaching 100*C just in 10-20 seconds at stock settings when all set auto(Vcore too) so when I OC to 3.8GHz set voltage to 1.225v so it took like 6 minutes to reach 100*C(1.14v Vcore stable and never reaches 100*C at stock settings with only vCore change)... I recommend staying under/near 1.25v(Under 1.3v is recommended) and stay under 70*C(Recommended)... Most PC well last at least 3 years and under if not stay under and use like everyday(Playing games mostly) and if change and stay under, it well last to 5-10 years... Higher Voltage from 1.25v decrease lifespan... Just aim for 1.25v at highest speed you can with CPU and Watch temps...
At the max VID voltage of I think 1.37 Intel warranties the chips for three years. Most people are running with much less and tend to get obsessive about heat. Try to keep it around 1.3v or preferably lower, the temperatures reasonable say 70c or so while rendering/benching, 55 to 65c while gaming and under 50c for the bulk of the time. If you do this the chip should last longer than you want it to.
Excessive heat is a long term killer, excessive voltage can be an instant killer.
Sandy Bridge is a hot CPU anyway because of everything the CPU is now sporting, Intel feels safe enough to supply the 3yr warrantied boxed release with it's pitiful stock cooling fan.
Since you're looking at overclocking guides your intentions are obvious, secure yourself the best cooling solution you can for the higher overclocks, so the CPU will run cool enough to last a long time.
The max Intel tested voltage for the Sandy is 1.520v, there's a link to Intel's website in my OC guide, regarding their testing and the max tested voltage.
Now you might bench at 1.520v, but I'd never recommend any long running at that voltage level, but it can take it, mine definitely has.
The wonderful thing about the Sandy Bridge CPUs are their overclocking versatility, you can OC a little, or moderate, or medium, or aggressive, or flat go for it, and as long as you keep it cool as possible it will last as long as it lasts.
There's no guarantees in life expectancy of a CPU, just factory warranties.
I've personally seen some insane cases where a forum member ran his C2D at 1.9v with watercooling for over 9 months.I have also seen some cases where others killed their motherboards or made their cpus unbootable without crazy voltages by using 1.5v for a few months.It depends on the part you get.To play it safe though,I prefer keeping my voltages below 1.4v and my linx temperatures no higher than 3c more than the max allowed temp.All these for 24/7 use.When benchmarking gets mixed up too then I stop worrying too much and go as high as I can before throttling occurs so that I achieve maximum results.
Reason i'm asking is i can't get over 4.4GHz without exceeding 1.35v. This is has nothing to do with heat though as my temps are 54/59/59/55 running prime at 4.4ghz.
Ideally I'd like a 24/7 47x or 48x but either my i5 sucks, the p8p67 sucks or i'm missing some bios settings cause most people seem to do much better at lower voltages. To get 5GHz stable-ish (i only tested for 10 min on prime) it took 1.52v. That put my individual core temps from high 60s to low 70s.
So is it ok to put a maximum heat limit of say 65 (avg of all cores) and not worry about voltage (though keep it below 1.5)?
Also, are these voltages the ones from the bios settings or cpuz readings? They're never the same unless i have llc on extreme.
DOnt ever never go over 1.4v but only if your testing like few hours or a day or so but dont go 24/7 over 1.4 or 1.35v... Just stay in the mid 1.3v than your fine but i still recommend staying near 1.25v which should get you around 3.8GHz OR a bit lower since AMD likes voltage....
That's unfortunate...I'm unfamiliar with SB settings(can't afford an upgrade currently). Work on your settings a bit more and if you don't manage anything, well just stay where you are . See if you feed a cpu too much voltage for a long time, it will gradually need more and more voltage to work at the clocks you have it at. I think you will be satisfied with 4.4ghz as the cpu won't be no slouch for a few years.
I think i'll try the stuff from ryan's guide, seems a bit different from what other guides say. I have all summer so between games and modding my case i should have time to experiment and maybe get my 4.7 or 4.8. Doesn't really make a performance difference, just some awesome sauce.