I've always wondered why hardware manufacturers don't use better thermal paste on CPUs. When I build PCs I would always replace the stock thermal paste and the cost was always pretty minimal and that was without the economies of scale they'd have. If this small thing helps so much why wouldn't they use it? What is the down side?
What I've heard is that CPU manufacturers (intel specifically in this case) optimize for consistency over time - the crappy intel thermal paste will still be the same level of crappy in 10 years time but a lot of (much) more effective enthusiast stuff might degrade and stop performing as well before then.
Of course I don't remember where I heard this, nor do I have any sources...
The gain is low, it increases costs, and better thermal pastes are electrically conductive so applying them industrially is a more complex endeavour (as you absolutely can't risk leaking/spreading them to any component). The risk/reward just isn't there for manufacturers.
