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I was told many years ago to do this by someone who at the time knew more than I did. The CPU was a celeron in the Pentium 2 era. It ran cooler with the toothpaste between the chip and the heatsink than what it did with nothing between.
Has anyone else ever heard of or tried this? What were the results?
RichieACC
Posted 2010-01-29T11:29:40.093
Reputation: 908
71
This is the standard "saran-wrap-in-place-of-condom" question. While some toothpastes may provide the correct type of thermal conductivity, "toothpaste" is too big a category to answer the question accurately. Worse, unless you want to make it a fun science project, nobody is going to be testing different types of toothpastes for thermal conductivity.
That said, the answer is probably "yes." Toothpaste is definitely better than nothing, because air (i.e., nothing) is a terrible heat conductor. That said, there are other properties to consider. From Wikipedia
I think that toothpaste might work for the thermal part, but you might have other problems in the short- or long-run.
On A Different Note: That said, if you need to stick a note to the wall, you can definitely use chewing gum (after chewing a bit). Sometimes it's hard to get off when your lease is over, though :)
Dan Rosenstark
Posted 2010-01-29T11:29:40.093
Reputation: 5 718
Very nice answer! – RichieACC – 2010-01-29T11:53:01.520
How well would chewing gum work as thermal paste? – RichieACC – 2010-01-29T11:55:07.380
1@RichieACC, I don't know, but I would say to get sugarless. Sugar tends to change over time, attract insects, etc. – Dan Rosenstark – 2010-01-29T11:58:04.723
@yar - sugar also smells bad when it burns and leaves charred carbon everywhere. Stick with actual thermal paste. The processor you save may be your own. – Rob Allen – 2010-01-29T14:42:05.467
4Also, don't use thermal paste for your teeth. – skarface – 2010-01-29T15:34:57.157
1@Rob Allen, the idea that you need to stick with thermal paste begs the question. The question is, in an emergency, how bad is toothpaste? You run out of thermal paste, the server must be up in 5 minutes. Use toothpaste, lose millions of dollars, use gum... these are the questions a field surgeon must handle every day. Personally, I just change computers every few years, so I don't mess with thermal paste :) – Dan Rosenstark – 2010-01-29T15:42:34.397
18If you find yourself in a "server needs to be up in 5 minutes" situation with the processor in your hand you've really already lost. I can just imagine the postmortem on the hardware a few months later... "What's this all over the... toothpaste?!?!" In all reality though, get yourself a non-stick frying pan, put some toothpaste on it and see at what temperature it a) liquefies and b) smokes. If either happens under 150 degrees (F) you better off with nothing. – Rob Allen – 2010-01-30T01:00:43.413
6@Rob Allen, thanks man, please don't delete, this conversation should remain in the annals of Superuser forever. TRue about the toothpaste and temperature. Also true that a few months later you'll have forgotten about putting the toothpaste there, and then you're really screwed. – Dan Rosenstark – 2010-01-30T01:59:39.497
Yar was absolutely correct about the variability of toothpaste. Toothpastes are not people, not all are created equal, some are more equal than others. :-P But seriously, any two randomly selected toothpastes are practically guaranteed to have numerous, large differences. – Synetech – 2013-12-13T01:38:27.840
11
I remember hearing about this at Dan's Data a while back, and he went back and forth with Arctic Silver's Nevin on the issue.
I think the basic idea was that toothpaste will dry up faster than true thermal paste, perhaps leaving you a lot worse off than if there was nothing at all. So, if you like removing your heatsink as much as I do, then no, it's not ok.
hyperslug
Posted 2010-01-29T11:29:40.093
Reputation: 12 882
1Whew!! I was beginning to think that nobody else had heard about this and that I was a victim of a rather mean prank!
Oh, wait, this does not exclude that as a possibility :) – RichieACC – 2010-01-29T12:01:56.930
brilliant icon, hyperslug. Good answer too – Dan Rosenstark – 2010-01-29T13:30:40.753
7
It might be better than nothing, but unless toothpaste has unsuspected thermal conductivity, I'd say it's a bad idea.
You also have to consider what the ingredients of the toothpaste might do in contact with your CPU. I suspect it would be pretty conductive in an electrical sense. You don't want electrical conductivity.
Better get some real thermal paste. It's more expensive than toothpaste, but worth it.
pavium
Posted 2010-01-29T11:29:40.093
Reputation: 5 956
+1 better than nothing, but certainly no replacement – William Hilsum – 2010-01-29T11:54:19.020
Water is excellent at transferring heat, but the toothpaste will dry up in a week or so. – Cees Timmerman – 2015-01-07T13:06:12.367
2@CeesTimmerman Surprisingly, it continues to conduct heat just fine even after it dries up. You wind up with dicalcium phosphate with some moisture still trapped and it retains substantially the thermal conductivity of water. It is vulnerable to cracking, but so are many thermal compounds. Corrosion is a risk though. – David Schwartz – 2015-03-11T00:43:39.733
@WilliamHilsum, @ pvium, but could it actually make things worse off? – Pacerier – 2015-06-18T10:21:21.203
5
Also just used toothpaste on my macbook pro 2011. It had a failing graphics card and being out of warranty I waited until it was truly dead => no boot. I took it apart, cleaned it and removed all plastic. Did a "reflow" of the motherboard in our regular oven at 220 degrees Celsius for a couple of minutes. Applied toothpaste to the cpu and gpu and put it all back together.
After all this it booted right back up. It ran hot for 2 minutes at 90 degrees Celsius. (might have been a diagnostic check after being taken apart, OSX just testing the insides) It now runs at 45 degrees Celsius under normal load. No crashes, no funky broken graphics cards stuff anymore.
It will probably set itself on fire at some point, but more likely because of the failing battery then because of the toothpaste.
Just to be clear: this is an old machine that has been abused for many years. I work as a photographer and this is the machine that travelled with me. So it saw lot's of water, dust, sand, mud and everything you don't want around electronics. Do not try this just because you are too lazy to get the real stuff.
Only badasses may proceed!
Update:
The gpu finally truly died. Well not really, the gpu is perfectly fine, even after months of having toothpaste for thermal paste. The solder connecting it to the motherboard however has too many cracks in it now and a reflow in a cooking oven no longer works.
RMenke
Posted 2010-01-29T11:29:40.093
Reputation: 161
1Wouldn't the toothpaste melt? – Pacerier – 2015-06-18T10:23:57.333
1No it dries up at the edges after a while – RMenke – 2015-07-06T09:44:14.277
Two questions: 1: Why would you heat a motherboard at 220 C? 2: Why couldn't you put a new solder? – Spandan – 2016-09-08T05:46:18.420
1: Because I googled reflowing a graphics card and found that somewhere. 2: I am in no way qualified to work on motherboards or solder things like that. I just needed my macbook to survive a bit longer. – RMenke – 2016-09-08T07:16:30.087
3
I put tooth paste between the heat sink and the CPU with the Colgate Total Advanced... It works like a champ!
If there will be an issue in the future, the PC knows how to protect itself, and it shut it off.
I used it on my 5 years old computer that I didn't care too much.
So far, again, it works great. I spread the paste with an old credit card, and cleaned the old paste with Lysol before I applied the tooth paste.
Yossi
Posted 2010-01-29T11:29:40.093
Reputation: 31
1
Good to hear. What are the temps of the toothpaste compared to the thermal paste under load and idle? This page says it's better than 8-year-old stock goop, but doesn't last long.
– Cees Timmerman – 2015-01-07T11:47:01.370@CeesTimmerman thanks for that page, I'm giggling like an idiot in a half-deserted office. – nthieling – 2015-07-30T21:56:45.850
There are older CPU types (first Athlon generations for example) that won't shut off before sustaining severe damage.... – rackandboneman – 2017-04-13T15:42:21.640
2
I've been using a rebuild with toothpaste on my Thinkpad T42 for about 3 years, with no problems. These laptops, however, are known for running cooler than most thinkpads, to begin with, and we don't play very many 3-D games on those ATI 9600's, so the load on the toothpaste is not very high. If you are worried about the paste drying out, just use A LOT. The only part that will dry out is the stuff on the edges of the CPU, and if you are generous with the paste, there should continue to be a large amount in the middle of the CPU that is thoroughly wet ... or use 25% vaseline and 75% paste... or 25% grease and 75% paste. Grease is basically oil & soap, to keep the oil from drying out.
Remember, toothpaste drops the temperature by 20 degrees, even after 12-hours of burn-in, and arctic silver 5 drops it by 29 degrees at most. So toothpaste gets you 69% to cooling nirvana, even after the dry-out period.
systemBuilder
Posted 2010-01-29T11:29:40.093
Reputation: 29
So your room is filled with toothpaste smell? – Pacerier – 2015-06-18T10:23:06.460
2
You acutally would be surprised.
In a pinch, yes, it is OK but a pinch is basically 12 hours.
If you want some other common goods, try this:
All of these ideas will help you in a pinch but ALWAYS get proper thermal paste.
riahc3
Posted 2010-01-29T11:29:40.093
Reputation: 234
0
You (or anybody else in kind of emergency) can just use regular (comestible) oil, or mineral oil which will be better if avail. for several weeks will work perfectly. Howerver, it will be mandatory to replace the oil with thermal paste after a while, because oil will polymerize and dry up in time.
Long time ago (in 198x) i did this for heatsinking high power audio transistors in a 2x300W amplifier, because thermal paste was not easily available at those times in Romania. The oil runs well for years, but the surface was quite large and thermal requirements were not so high as in modern processors (some 3 cmp per power transistor case versus less than 1 cmp for processor).
addysoftware
Posted 2010-01-29T11:29:40.093
Reputation: 1
73...just when you think you've seen it all – Manos Dilaverakis – 2010-01-29T11:36:34.887
3If this is true, then how to know which out of the many types of toothpaste to use? – Arjan – 2010-01-29T11:40:18.547
1Haha, I have no idea which toothpaste is best. I don't do this anymore. I now keep stock of the real thing. This was suggested after getting panicky about my machine overheating and the nearest store that stocks thermal paste being almost 200km away. – RichieACC – 2010-01-29T11:44:46.213
34The other question to consider is whether you can brush your teeth with thermal paste. That would be good for teeth.stackexchange.com... – Dan Rosenstark – 2010-01-29T11:57:17.347
2haha, it's abrasive enough, but does not leave that minty taste :( – RichieACC – 2010-01-29T11:58:53.193
29No idea if this would work to be honest, but at least your CPU would be protected against plaque build-up and gingivitis. – Kez – 2010-01-29T12:16:14.750
@kez: Provided the parts of toothpaste that do the protection survive being held against a 70 °C CPU ;-) – Joey – 2010-01-29T12:41:09.097
Just get thermal paste. It's safe and cheap! I heard MS used toothpasted on the XBOX 360's that had the RROD. :-) – Kelbizzle – 2010-01-29T13:55:52.270
10Thanks a lot. Now I've sprayed coffee out of my nose and down my shirt. – njd – 2010-01-29T14:36:35.027
11Send me your CPUs and I'll test them for you! I've currently got gell, baking soda, triple action and plain toothpaste, so 4 CPUs should be enough. – Ash – 2010-01-30T02:17:09.253
4I really enjoyed reading the responses and comments that were posted to this question. Thanks go out to everyone involved. – RichieACC – 2010-02-03T13:57:10.163
1Preparation H is used specifically for burning sensations, I wonder if it would work better than toothpaste? – Everett – 2012-07-25T13:33:35.237
I tried this and it did cool down the temperature of my CPU for about a month now. – Jürgen Paul – 2013-08-11T11:58:57.147
Semiconductor engineers measure expected transistor life by running transistors hot, recording how long it takes them to fail, and extrapolating to calculate expected life span at a lower temperature. For long life, it is VERY important to keep transistors from overheating. ... My point is they may continue to work for awhile, but you are definitely shortening their life. The only thing tooth paste and thermal paste have in common is that they are both a paste. Why not use pastry? Yes, there is a big difference between insulators and good conductors of heat. – Elliptical view – 2014-02-02T17:53:00.750
1I'm having a hard time finding Zinc Oxide based toothpaste. Maybe you should be trying some of that heavy-duty sunscreen, look on the label for Zinc Oxide content. <grin> – Fiasco Labs – 2014-02-02T18:02:24.817