But 100C is also pretty much Tjunction temperature anyway, which means reaching that temp will in fact cause physical wear and tear on the IC. The wear and tear would probably decay exponentially as you drop away from the Tjunction limit, but that still means you don't want to get too close to it in general.
The reality is that what seems "pretty warm" to your hand is nothing to a computer. 100C is hot for them. Dip your hand into some freshly boiled water. Is your computer that hot? Then it's fine. (Don't actually do this.)
It is also unclear to me that disabling frequency scaling results in a cooler computer. Someone should collect some data on how the power is actually used; does it use less power to perform a calculation for 2 seconds at 1000MHz or 1 second at 2000MHz?
Finally, my experience with overclocking is that it's AVX that really makes Intel chips heat up, regardless of frequency.
All in all, I think this probably does nothing. Personally I just use an iPad Pro as a laptop and keep my computers in a datacenter. No fans.
The 20% is worth it for me because the computer seems to be fast enough anyway.
What do you think the odds are in him realising this benefit? Assuming he bins the laptop after, say, 5 years? (he's rich enough to buy a £1.3k minimum laptop, assuming it wasn't second hand)
It relies on several assumptions: 1) His laptop dies before he bins it in 5 years' time 2) It died becuase of an integrated circuit (the reason he cites) - in my experience old computers tend to die of things like exploded motherboard capacitors rather than ICs. Maybe the death of these are accelerated by turbo boost, too? 3) The integrated circuit's death was hastened by a meaningful amount (several months at least; a dodgy thing dying a couple of days/weeks later doesn't save you from buying a new laptop).
Is taking a 20% performance hit on your laptop really worth this? I'm interested. I can't imagine it would be for the vast majority of people.