Thermal pads or something else for AMDs?

[Eteq]

The AMD web site says you should always use "PCM"s (thermal pads) on Athlons instead of thermal paste or grease... is this actually true, or are they just trying to keep things standardized or something?

 

[BlueWeasel]

Well, I got my retail 2000+ yesterday with HSF and the first thing I did was scrap off the thermal pad and use Artic Silver 2 in its place.

However, I think it voids your warranty if you remove the thermal pad and use paste/grease in its place, even if you still use the retail HS and fan.

I just think a thin layer of AS2 is a better for heat transfer as compared to a thick thermal pad. I didn't do any tests to confirm, but I think most here would agree with me.

 

[LostHiWay]

I think the only reason AMD recommends a pad over themal grease is because grease can dry out. I know the Radio Shack does after about a year or so. Artic silver I'm not sure about since I never have left my heatsink on for more than 6 months, but it's not suppose to.

AMD is just playing it safe for the people who buy a retail CPU and don't touch it again for 3-4 years after they install it. I'd recommend AS3 though unless you're really concerned about the warranty.

 

[cautery]

Primarily, the reason AMD uses the phase change material is 1) It's easy to appply in an automated process, and 2) The material acts as a little protective cushion when you install it the first time...

With that exposed and very brittle core, you can crack a corner/edge off in a heartbeat, if you are not careful...

Once the phased change material gets to its melt temp (which it will the first time you fire it up since it's so thick between the core and sink), he sink settles down to the core...

Then the sink cools the proc down below (theoretically) the phase change temp, and the stuff solidifies again forming an "acceptable" thermal interface with the core, and as a side benefit... it kinda forms a little pocket around the die slightly increasing stability...

IF you are careful, you can get MUCH lower total thermal resistance using a premium thermal interface compound.