Thermal compounds

I'm trying to compare dynex and arctic silver 5. Yeah I know you guys will say AS5 no matter what. I'm just trying to understand something.

Dynex says it has 9.2428 W/m.C thermal conductivity.

AS5 says it has 350,000W/m^2 °C thermal conductivity.

This seems to me to be 2 different units of measurement. Can someone help me compare the two?

Thanks.

 

I'll be hoenst, I haven't ever looked at those numbers. But to be perfectly honest why bother? Artic Silver 5 isn't really going to make much diffrence from using whatever came preapplied to a heatsink. The diffrence between using what the heatsink shipped with and using AS5 is about 1C when you actually test it. So what's the point. Is it really worth the extra 50 bucks you have to spend just to get a tube of the stuff?

 

50$ for AS5 ....if ya whanna go expensive go [font=Arial, Sans-Serif]diamond[/font] .....I googled AS5 vs. Dynex and dident get any thing and i dont understand the # ether....Like Coco said the dif. is so small thare realy is no point in less your overclocking or live in the middle of the desert ........

 

If you check Arctic Silver's page on AS5, you'll find that it reports the figure you quoted as "Thermal conductance". The Dynex figure reports thermal conductivity. Conductance and conductivity are not the same units, and they don't measure exactly the same thing. The page at <http://www.answers.com/topic/thermal-conductivity> may help a little with that.

It seems picky, I know.

Both figures are measures of a material's ability to transfer heat, but it may not be possible to convert one measurement to the other. I haven't figured out what the difference is. I found several thermal unit conversion utilities on the Web, but I didn't find any that would deal with that conversion.

The conductivity figure seems to be the more common measure; on that scale, silver measures at 406 W/mK, copper at 385 W/mK, and aluminum at 205 W/mK. The reason you don't want any air under your heatsink is because it measures 0.024 W/mK.

And the reason why you want your layer of thermal paste to be as thin as possible while still eliminating all air from the interface is because thermal pastes are not good conductors of heat. Quartz has a similar conductivity, i.e., 8 W/mK. Thermal pastes are just a lot better than air, which is what you get in there if you don't fill the gap with something else.

Thermal conductivity figures are subject to some variation, depending on who measured them and under what circumstances. It seems that the science of heat transfer is subject to some argument.

But which is the better heat transfer medium -- AS5 or Dynex? I've no idea. Maybe someone else can point us to a review that compares the two.