Heat compound and reliability

Last Updated on January 28, 2021 by Dave Farquhar

It’s known by many names. Heat sink grease. Thermal compound. Heat sink compound.

It comes in tubes or syringes. Cost varies from a buck or two to twenty. The cheap stuff is plain old grease. The expensive stuff is made of exotic materials including silver.

Everyone agrees compound makes heat go from the chip to the heatsink above better. Everyone disagrees over what’s the best to use. Holy wars ensue. Feelings are hurt. Egos are bruised. Money is wasted. Passive voice annoys.

Dan’s Data did a comparison of four different compounds. He also included two rather unconventional–ahem–substances. What did he find does the best job of conducting heat between a CPU and a heat sink?

Toothpaste.

Dern. I was rooting for the Vegemite. (At least the Vegemite beat out Arctic Silver.)

I’m sure you don’t believe me, so you can read about it… I won’t give you the URL just yet. Dan’s point was that there’s no measurable difference between different things people use as thermal compound. So there’s very little point in paying $20 for a syringe of exotic compound. Being a tightwad and using a glop of toothpaste isn’t a good idea though, because it’ll dry out too quickly. Plus it’s apt to cause other problems. But there’s nothing inherently wrong with the $1 stuff. The real key is–against conventional wisdom–using a thin layer of the stuff you’re using. Remember preschool, where we all thought since a little glue holds things well, a lot of glue must hold it even better? Same principle. A little dab’ll do ya.

This was certainly the most amusing hardware story I’ve read in a long time. Give it a look.

The major difference between thermal compounds is how long they last. Here’s how often to replace it.

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4 thoughts on “Heat compound and reliability

  • March 13, 2002 at 11:02 am
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    Hum, you could always brush your CPU at night after your teeth to keep the toothpaste fresh.

  • March 13, 2002 at 11:54 am
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    I use Arctic Silver II. I guess I fell for the hype. It works for me, and I have a LOT of it left (after four applications).

    By the way, Dave, check your inbox later this week for what I think will be an interesting e-mail from me. It’ll get you thinking, and it may even provide some material for the site.

  • March 14, 2002 at 10:09 am
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    Hi R. Collins Farquhar IV,

    Nice to read your opinion. What configuration would you recommend for a simple print server?

    Thanks,

    Bruce

  • March 14, 2002 at 12:35 pm
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    The main point is that there shouldn’t be an (insulating) airgap between the processor and heatsink. So applying a bit more grease than nessesary won’t harm.
    A nice fat droplet of high temperature industrial grease does the job for me.

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