After a somewhat lengthy and technical talk with b2 (banthracis) I've come here to get all my half-answered question answered properly.
I am already familiar with overclocking in general and have successfully overclocked the cpu in my computer (late at night when everyone else was asleep because they think it'll absolutely kill it if I o'c)
I do however still need to grasp some of the concepts of longevity, heat and voltages.
I originally thought (before banthracis helped me out) that o'cing on stock voltage would increase heat a bit, enough to notice and possibly be looking at, but nothing massive. After b2 told me more about it, in summary he said that the heat increase when o'cing on stock voltage is so negligible that it's not going to be ... well .. big enough to even bother thinking about.
So what sort of change in the longevity of the cpu would I be looking at if I were to find a completely stable overclock on stock voltage (benchmarks run for hours without problems, not noticeable stability issues) compared to both a higher stable overclock on a higher voltage and also compared to the the stock speed and voltage? (by cpu life I don't mean futureproofing, I mean how long will it chug on until it dies)
thanks, especially if you understood that well, since I got lost
btw, I'm talking about both stock cooling and decent budgetish aftermarket cooling like the Cooler Master Hyper 212+
I know there's lots of threads around about this sort of thing and yes I have gone through and read 3 or 4, but my brother's convinced that he knows a lot about computers when he actually doesn't so something about current tech would be needed... cos he says that it's gonna completely screw it and we all know he's wrong.
It all depends on how high you go. Since you don't state your CPU, I'll give an example with mine: i5 750. The (new) Intel specs for maximum voltages are 1.40V Vcore and 1.40V Vtt/IMC. Stock volts are something like 1.15V Vcore and 1.08V Vtt or thereabouts. Now, firstly, OCing at stock volts is completely safe. Core speed doesn't really harm the PC it's the voltage that will melt it. If you want to make it go a little faster, let's say you go from 1.15V to 1.25V you should still be totally safe for a long time. However, as you approach the voltage limit you are getting riskier in terms of longevity. Intel states that if you go over their specs, longevity will probably be negatively affected, however, returning to stock settings should something go wrong should allow it to continue to function for a some time.
As for heat, speed doesn't really make heat. The heat comes from the power usage, so more voltage = more power/heat. Again, depends on you CPU but they all have a max running temp from the manufacturer. Intel says for my CPU it's 72C.
I'm running my CPU OC from 2.66ghz to 3.68ghz, voltage from 1.15 to 1.306 Vcore and 1.08 to 1.206 Vtt, and my max heat reaches 62C under stress testing (which it never reaches under normal usage). I fully expect my CPU to last several years like this.