Usually the safety temp limit is 60c-65c. But CPUs can go hotter than that. But todays cpu have temp threshold and that it will automatically throttle down or shut down the operation when it gets too hot.
At the mean time here's some good video about removing HSF off of the cpu while in operation.
My 805 was 50c idle. 100% would shoot to 78c with cpu fan full blast
That was OC to 3.5Ghz
Seemed to survive just fine, tho i wouldnt suggest u run it flat out all day at that temp.
Temp does have direct influence on CPU lifespan
But when its an 805D.... who cares if it only lasts 9months!
Honestly, I do not know why you are all so fixated with the lowest possible temperatures in the CPU die. What the hell do you care if a core is at 50C or 70C? If it doesn't crash under stress testing - what possible difference can it make?
Look, I know the physics of the CPU heat death - and the high temperatures in modern CPUs under overclocking have essentially no impact on usable life span of a product.
Sure, cooking your CPU with overclocking will eventually kill your CPU, BUT (and it's a big but!) the life time will merely have dropped form 15 years to 5 years.
Are you telling me you plan to be using that CPU in 5 years from now? Hell, even if you baked it to within an inch of its life, you still wouldn't be using that CPU in 3 years from now.
Users need to understand that it is HEAT CYCLES which break a CPU. The maximum operatign temperature really doesn't have much effect on life span, EXCEPT insofar as the increased temperatures are caused by increased voltage supplied to achieve stable overclocks. The over-volting of CPUs is the most harmful thing you can do to them. This hastens the process of electro-migration and the voltage literally starts pushing metal ions around the core, eventually killing thousands (or indeed, millions) of transistors in the core. CPUs are highly fault tolerant, (You can burn multiple holes right through a CPU using a laser, without killing the core) so they'll keep calculating successfully for a very long time, albeit at reduced speeds, which is counter to what you wanted when you overclocked in the first place...
If you run a CPU hot, it is better to leave it running 24/7 than to turn it off at night, and start it in the AM: that's just adding another damaging heat cycle to the core.
So, the answer to the big question is this: it doesn't matter what temperature your CPU is, provided that the CPU is stable.
I am dealing with a similar issue right now, and my understanding is that if your CPU is running 55 during normal operation, you are in good shape, even if it spikes higher during games occasionally. This might be a bit conservative (pun) but why test the threshold. If you want to push it, go to 60 at normal operation.
Why did I even bother reading this thread... And 14 yrs old.. man... when i was 14 years old... I can't even rmr what grade that was... probably freshman year... of high school... sigh...
And uh... Mobius answered the question, but I still like to keep my cpu relatively cool, if the HSF suddenly dies on me, I don't want my cpu to possibly overheat (yeah, thermal throttling, but still murphy's law > me)