Originally Posted by The Radius Kid
Eeyup....valleys full of air.
The big question is why would air be worse at transfering heat than metal filled paste?
Ultimately,every home computer is air cooled..unless you're using a geothermal loop.
Air is a notoriously horrid conductor of heat. That's why we have air and gas-paned windows. It's a GREAT insulator of heat.
Originally Posted by MikelKassner
Either way the point is, and so far I am proving it very well, that thermal paste is an option, not a requirement, at least when it comes to lapped CPUs and heatsinks.
Originally Posted by Vap0r87
I feel like a lot of derping is going on here because people have been instructed to always use tim. The surface of HS contact will always have better thermal conductivity than a thermal paste will. Its like comparing jello to water for drink-ability. If he somehow managed to get a perfect lap hes better off not gunking it up. With all that said I don't think perfect is easy to come by and would recommended a very liquid like tim, so when its applied it spreads over the whole cpu with a very think coat. Use only a little.
Originally Posted by MikelKassner
Yeah their has been a good bit of it, some people can't get it through their head that their are ways to get around using TIM, my results would of been much better if I didn't have apparently the worst stock Phenom II cooler ever made, seems idle temps on it are others load temps with or without TIM, but testing will be redone after I order a new cooler.
Allow to me to elaborate on my last post. I'm a mechanical engineer with a background in heat transfer.
No heatsink surface is smooth.
No matter how mirror-like it appears, there are still countless crevices that are negatively affecting your heat transfer. These crevices, filled with air, act as insulators.
No heatsink surface is flat.
I don't care if you used 1000000 grit sandpaper and the flattest surface in the world to lap against. Unless your 100% flat heatsink sits flush and even with a 100% flat CPU, some areas of the CPU will NOT be touching the heatsink. What does this mean? That gap is filled with air, the same dreaded insulator just mentioned.
TIM (a great heat conductor) fills the microcrevices producing a surface that can now transfer heat through its entire surface. TIM also fills in the gaps produced by two surfaces not identically flat or two surfaces not evenly mounted (did you screw your heatsink to the backplate with exactly the same torque on all four screws?).
Can you get by without using TIM? In some cases probably. Consequently, your heatsink is now noticeably less efficient, and without improved fans, may cause your CPU to overheat. Lapped your heatsink? Use less TIM. Don't use none.
Lets consider some pros and cons of NOT using TIM
- Save $0.10 (0.005% of your computer build cost)
- Major risk of CPU overheat and/or $100+ loss
- Voided warranty
- Need bigger heatsink
- Need faster fans
- Use more electricity to power faster fans
- Deal with louder computer due to faster fans
As I said before, this should be a no-brainer to use TIM. It's one thing to question how necessary a particular mass-marketed component truly is (who really needs a $90 1900g copper heatsink for a 90W CPU), but it's another to argue against a proven product to save you $0.10. For a community of people trying to achieve the fastest and most reliable overclocks (and spend serious $ to do so), it makes absolutely no sense to bypass such a cheap, easy to use, and critical component of your cooling system.