DIY CPU Thermal Grease, Using Diamond Dust 210
tygerstripes writes "The dysfunctor has spotted an impressive project over on InventGeek.com; an innovative chap has developed his own thermal compound for improved CPU cooling, using diamond dust — the best available material for thermal conduction — as the key ingredient. In spite of the quick-&-dirty DIY nature of the project, the gains in cooling performance are remarkable, especially considering the material cost was only $33. Given the price many enthusiasts will pay for a top-end cooler, it's easy to imagine this product coming to market quite soon."
Re:Diamond dust is cheap? (Score:5, Informative)
not in the incredibly low grade diamonds that aren't used in jewellery. Very small, damaged stones with poor colour (the kind that don't even qualify for the 4 C's) are used in industrial settings - ex. diamond saw blades.
Re:Diamond dust is cheap? (Score:5, Informative)
bottom line (Score:5, Informative)
I'm gonna throw out a spoiler: In a test situation, at full load, the best temperature under Arctic Silver was 57C, while this diamond dust compound achieved 38C. The nearly 20 degree difference is huge, and would definitely make a difference in overclocking. I'm hoping the price can come down when produced in industrial quantities, because it'll be enormously worthwhile.
Re:Diamond dust is cheap? (Score:3, Informative)
been done before (Score:0, Informative)
Existing for several decades. (Score:5, Informative)
This technology is not new. Diamonds have been used as heat sinks and thermal conductors for processors in sattelites since the 70s (natural diamonds in big sizes, so expensive). Since about 1992 there have been succesful efforts to sinter diamond dust (waste material from the polishing process of gemstones, and now increasingly synthethic diamonds, both are not expensive) for use in thermal conductors.
Re:Diamond dust is cheap? (Score:5, Informative)
Nope. Jewellery is nowadays just a little part of the worldwide diamond industry, and while it often uses natural, mined diamonds (mainly because some weird people with bucketloads of cash want to be sure that the diamond they wear is natural and mined, even though it is perfectly possible to produce a diamond of equal aesthetic value in a lab), which are quite expensive, the biggest demand for diamonds is in the tools industry. Most of it goes into production of diamond-tipped cutting tools (which are actually coated in diamond powder or small diamond shards, not made of solid crystal) for the market, the rest is used to make specialized cutting and grinding elements in machines that produce solid carbide tools.
Just check eBay or your local hardware store for the prices of diamond-tipped tools - they're only about twice as expensive as high-quality HSS and often cheaper than good solid carbide cutters, because they're actually just HSS with some diamond powder coating, easy and quick to produce.
Diamonds can be made industrially (Score:5, Informative)
Look up Gemesis and Apollo. Technology has progressed to the point that we can synthesize diamonds. I don't mean make cubic zirconium, I mean real diamond, made in a lab. It is still expensive in relation to a lot of materials, but it is cheaper than mined diamonds, and getting cheaper.
B&W use it for their tweeters in their high end speakers, as an example.
Re:54C, not 57 (Score:2, Informative)
Well, you were kinda right *both* times... it was 57C before "curing" and 54C after curing. The diamond dust mixture was 38C immediately.
Slashdot or SlashMold? (Score:5, Informative)
That guide was posted a while ago...
Here is a company that sells it premixed and has been around for several years.
http://www.innovationcooling.com/ [innovationcooling.com]
An idea that was recently (2 days ago) discussed on Hack a Day was using diamond stropping paste
http://hackaday.com/2009/08/03/diamond-thermal-paste/ [hackaday.com]
Here is a reliable review of Diamond thermal paste.
http://hardwarelogic.com/news/137/ARTICLE/2752/2008-03-03.html [hardwarelogic.com]
As far as just hoping on Ebay and buying your own, good luck. Finding a distributor for your dust and suspension will take you some time.
I think the most important thing people should consider and hasn't been mentioned so far is that the equation for heat transport is linear. Changing the adulterant in the suspension will be more noticeable as the temp increases. IMHO for most people it's a total waste of materials, for some people it's a decent alternative, and for a very small number of people it's a good idea to spend the time locating materials to make a batch.
Re:Diamond dust is cheap? (Score:3, Informative)
Since no one reads the article... (Score:4, Informative)
Idle - Max load
42c - 57c - Arctic Silver with a fresh application
39c - 54c - Arctic Silver with 2 week cure
29c - 38c - Diamond Grease with a fresh application
These numbers are almost too good to be true. A 19c drop under load with diamond paste? With my 4GHz OC'd system, I'm happy getting 38c when idling. If this data is true, it will really be revolutionary.
Re:Diamond dust is cheap? (Score:4, Informative)
Re:bottom line (Score:4, Informative)
It's also enormously worthwhile to just put the right amount of thermalpaste on your cpu and mount it properly, something which will get you the same temps he recorded with his diamond dust compound (coughICdiamond7cough) with just about any of the other aftermarket pastes.
Quick Google search (Score:1, Informative)
produces something available for order. No reason to DIY.
http://www.heatsinkfactory.com/ic-diamond-24-carat-thermal-compound.html
Re:Where did I put that? (Score:1, Informative)
here.
http://www.heatsinkfactory.com/ic-diamond-24-carat-thermal-compound.html
Re:Finally (Score:5, Informative)
Commercially available here [heatsinkfactory.com]
Re:WHY TAGGED HARDHACK? (Score:2, Informative)
Hardest "natural" material on earth. Aggregated diamond nanorods are currently the hardest.
http://en.wikipedia.org/wiki/Diamond_nanorods [wikipedia.org]
Sorry to be a bastard, but I'm a bastard.
Mod parent up! (Score:5, Informative)
The type of paste you use has very little difference. Let's not forget this comparison which includes toothpaste [dansdata.com].
Re:bottom line (Score:4, Informative)
There is a manufacturer: http://www.innovationcooling.com/ [innovationcooling.com]
Re:Diamond dust is cheap? (Score:4, Informative)
Or, it could just cost $7.99 [heatsinkfactory.com]. I guarantee 1.5 ounces will last you at least a dozen installs, if not more.
I agree. Bad math and bad physics in the article. (Score:4, Informative)
I was going to just mod you up, but I figured your post would soon be at 5 anyway. (if not, mod parent up!)
Yes, you're absolutely right. Lots of bad physics and a completely incorrect conclusion in that article. If there is an improvement in the thermal interface, the heatsink should get HOTTER. All of the heat goes somewhere. That's the first law of thermodynamics... conservation of energy.
You can break it down to a thermal resistance model which is functionally equivalent to an electrical resistance model. Difference in temperature is the "voltage" that drives the flow of heat (current). The heat (current) is a fixed value. The resistances are the various materials the heat has to flow through to get to the air. It can take many parallel and series paths to get out and you can build a resistance network to calculate heat flow through each "path". One way is through the IC leads, into the board, and eventually to the air... or the most direct path is through the heat spreader, through the thermal interface material, into the heatsink and eventually to the air. If the heatsink reads a lower temperature, that means less heat is flowing through the heatsink and that heat is taking a more difficult path to get out and thus the IC junction temperature is HIGHER. That's BAD.
So yes, the math doesn't add up. The thermal interface between the IC and the heatsink should be spread so thin that the thermal resistance across it is almost negligible. Thermal grease is only there generally because it's it's much higher conductivity than air and if you don't have it, all you have is air in all of the little surface imperfections of the heatsink and heat slug on the IC. Adding solid particles to the grease only serves to hold the heatsink and IC heat slug further apart, so even if it's great conductivity, it's generally the wrong thing to do.
-S
Re:bottom line (Score:5, Informative)
Thanks to your comment, I found the video you were talking about:
http://www.youtube.com/watch?v=MZOsSPsTYi0#t=3m10s [youtube.com]
Re:bottom line (Score:4, Informative)
Thermal conductivity is a function of the materials in use, not what it's pushed up against.
Copper rates at 401 W/(m-K), diamond rates at between 900 - 2320 W/(m-K). 2320/401 = 5.79.
Now, we're not comparing pure copper to diamond, but it's entirely possible that the compound they're comparing to is that much "worse" than their own.