Diamond-cooled GPUs are coming soon — startup claims 20C temp reduction, 25% more overclocking headroom as it seeks US govt funding for diamond-encrusted chip cooling solutions

you know they're used as a cutting tool

This is a substrate, the piece that holds all the parts of a CPU together and that is currently made using fibreglass

Except man made diamonds cost pennies to make compared to natural diamond

It's not as if they're using diamonds hand-mined by children in Africa or something... That's the jewelry market. Synthetic diamond is in a ton of stuff, and it's not really that expensive. The "material" is just carbon.

Natural diamonds aren't even rar, it's just one big business family owning pretty much every mine on earth. Even jewelry diamonds could be very cheap without artificial price manipulation.

However they'll use artificially produced industry diamonds for CPUs. Since they'll be very tiny and purity probably doesn't matter too much, this is likely a relatively cheap process too. I doubt they'll want to lose on revenue.