thermal compound when changing processor?

If you have one of the newer CPU's including the Prescott, I would use an Arctic Silver compound. The most recent tests show their Ceramic formula to be better than Arctic Silver 5 and it is non conductive. The instructions Bev gave you are good, but the new method of putting a drop in the center does not always work well. The CPU spreader (flat metal cover) is used to spread the heat from the core's hot spots and you need it covered to work efficiently ( you will see many posts where it is said the core is only a small square in the center of the spreader and that is all that needs to be covered, but the whole spreader surface transfers heat. This is especially true on some of the newer spreader designs). I used a piece of tempered glass as a test and pushed a heat sink down on the glass with a blob of thermal paste centered in a drawn square. If the blob is not uniformly round, it spreads to the area it is heaviest. If you can get a uniform blob centered, it works pretty well.

My suggestion is to spread it thinly over the CPU heat spreader with a credit card (old method) or try the glass procedure (glueing some guide strips the size of the heatsink contact with the spreader square marked inside) until you get the feel for the right amount and the uniformity needed. My opinion is just that and may not be something everyone agrees with, but it has worked for me keeping my OC'd systems running pretty cool.

 

Message Edited by dogin on 02-17-2006 09:26 PM

dogin -

I think I'm going to reseat my heatsink using your method. I installed a larger heatsink following Artic Silver's instructions and I swear my temp went up 1c. And I waited 200 hours of use, as recommended, before I took my measurement. This time I'll spread it on like cream cheese on a bagel. lol :smileyvery-happy:

herb366, Know you are just kidding about the cream cheese spreading on the bagel (I put it on heavy) , but maybe a diet spread barely covering it. Yeah, on most of mine, I have noticed a 2C-3C decrease in temps. Got a little concerned on one where I had tried the blob in the center and it got hotter and when I took the heat sink off the core would not have been fully covered let alone the spreader. Thats when I tried the glass test method to see what was happening.

dogin, I bookmark so many articles I want to read that it takes me a month to find them again. lol :smileyvery-happy: I haven't read it yet but here is a 12 page article that I ran across last month on how to use thermal paste. http://www.hardwaresecrets.com/article/274 Who knew thermal paste was such a big deal. :smileysurprised:

Article made a good point of twisting off the old heat sink using heat to free it up so you don't pull the old CPU out of the socket. I always run the computer to heat it up before removing the old heat sink, but a hair dryer could work as they indicated . Saw where they at least spread the thermal grease somewhat, but still use the pressure of the heatsink to do the final spreading (I still prefer covering the whole heat sink with a thin layer). Some of the newer CPU spreaders have copper layers that are needed to fully disapate the heat and the full surface transfer is definately needed. Saw where the new 955EE reaches  95C under load at default clocks. That core needs all the help it can get! 

Message Edited by dogin on 02-18-2006 12:21 PM

I let my pc cool off before switching out the processor thinking that the parts would be easier to handle. I almost had a heart attack when I lifted off the heatsink and saw the cpu attached and ZIF lever still locked. I couldn't pull them apart and the hairdryer trick saved me from doing some nasty prying. I think I'll spread the thermal paste close to the edge of the heat spreader. I think the Artic Silver instructions say to use the equivilant of one/two grains of rice in the middle and then move the heatsink back and forth. I don't know about other heatsinks but there was virtually no give in mine. It will be very interesting to see the spread pattern of the thermal paste when I take off the heatsink.