metal_dragen, on 07 May 2012 - 11:18, said:
Don't forget to clean off the existing compound first - use acetone or isopropyl alcohol (can be found at hardware stores or pharmacies). And be sure not to touch the surface with your bare hands once it's clean.
that's pretty much required if you want to be SURE everything is good.
so clean off old past from CPU surface AND heatsink surface with isopropyl alcohol to where it's completely clean and dry and then apply the usual bb sized (or a hair smaller) in the center of CPU of thermal paste and then apply heatsink like usual.
while people's opinions vary on what method is best for applying thermal paste i think the general consensus is the small bb sized (or a hair smaller) drop of thermal paste in center of CPU and let heatsink spread it out when clamping it down method is most fool proof/easy consistent way to spread the thermal paste for you as it helps prevent air bubbles etc they say as other methods seem a bit more risky.
and like he said don't touch the surfaces with your fingers as they say the oils from your fingers can hinder cooling quite a bit.
i usually use something to scrape off the old thermal paste off the CPU/heatsink (be careful not to scratch it so don't use anything that can damage the surfaces) to get the heavy stuff off and then use the isopropyl alcohol on the end of a q-tip and swash that around a bit to clean the rest of it off and then you could probably use a paper towel once it's mostly clean and wipe the surface to make sure there is no left over residue on the CPU surface and that it's totally clean as you can tell by looking at the paper towel to see if there is any obvious grey gunk on it from the old stuff and once there is none and it's clean i do basically the same to the heatsink side as the heatsink side seems to require a bit more effort to get clean as the i3-2120 CPU (and stock heatsink) i just installed recently took me a while to get the heatsink surface clean as it's got more of a rough looking surface on the bottom of it so it took me a while to get the thermal paste off that comes pre-applied.
p.s. they say it takes around 200hours of use for the 'Arctic Silver 5' paste to be at it's best so i probably still have some cure time left on my recent build. my temps 'may' have already dropped a bit vs when i first installed it and ran a CPU torture test not long after but i have not ran the torture test since i first ran it to know for sure plus it's roughly 4-5f colder in my room at the moment so that i suspect could make it appear to have lowered temps. right now as i am encoding something with x264.exe (which hammers your cores pretty much at full) i am floating around 52-55c on CPU temp (room temp = 72.5f). granted that don't hammer your CPU as hard as Prime95/IntelBurnTest etc but it taxes it pretty good which will probably be roughly the max a regular game or application will run which is more of a real world CPU heat test vs Prime95/IntelBurnTest/LinX which is more of a worst case scenario of how hot your CPU will get.
speaking of LinX (CPU torture test app) when i ran that on my old CPU it seemed to raise heat about 1-2c more than Prime95 did. but i have not ran it on my current CPU yet but i probably will semi-soon.