LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices



Reply
 
Search this Thread
Old 09-02-2011, 01:34 PM   #1
stf92
Senior Member
 
Registered: Apr 2007
Location: Buenos Aires.
Distribution: Slackware
Posts: 3,268

Rep: Reputation: 49
Thermal contact grease between the CPU and cooler?


Hi:

Between a socket 370 Celeron and the cooler ought there be any thermal contact grease? Thanks.
 
Old 09-02-2011, 01:36 PM   #2
{BBI}Nexus{BBI}
Senior Member
 
Registered: Jan 2005
Location: Nottingham, UK
Distribution: Mageia 4
Posts: 4,305

Rep: Reputation: 205Reputation: 205Reputation: 205
Short answer, Yes there should.
 
Old 09-02-2011, 03:27 PM   #3
screwbottle
Member
 
Registered: Mar 2004
Location: Johannesburg South Africa
Distribution: Ubuntu
Posts: 38

Rep: Reputation: 19
Lesser processors like a Celeron could also have a thermal rubber type cooling mat between the processor cap and the heatsink, but yes a special thermal paste is applied in the majority of cases. It has a simple process, although complex in how it does this, firstly it fills in the micro uneven surfaces to create a smooth contact between these surfaces and to transfer the heat rapidly between the surfaces. A very thin layer is applied. Hope this is what you are looking for in an answer.
 
Old 09-02-2011, 05:42 PM   #4
stf92
Senior Member
 
Registered: Apr 2007
Location: Buenos Aires.
Distribution: Slackware
Posts: 3,268

Original Poster
Rep: Reputation: 49
That is, indeed.

About the mat, it is the cooler that seems to have one, though I can tell for certain. I feels different the the sense of touch than the rest of the cooler but maybe it's because of the old grease deposited on it.

I intend to remove the silicon grease anyway with isopropyl alcohol. Thankks.

Last edited by stf92; 09-02-2011 at 05:52 PM.
 
Old 09-02-2011, 11:19 PM   #5
jefro
Guru
 
Registered: Mar 2008
Posts: 12,078

Rep: Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520
Less is more in this case. You don't need to remove old grease. It doesn't go bad.
 
Old 09-03-2011, 07:41 AM   #6
warpuck
LQ Newbie
 
Registered: May 2008
Location: michigan
Distribution: ubuntu
Posts: 9

Rep: Reputation: 0
any non-conductive grease will do

Jefro is absolutely correct.
I have replaced cpus in laptops reusing conductive mats. What works for me is isopropanol, mineral oil & artic silver. I mix that all together & use the head of straight pin, once,,, to put that mixture on the middle of the cpu and clamp it down. I dont bother to spread it, the clamping pressure does it for me. This has worked well so far.
 
Old 09-03-2011, 09:41 AM   #7
stf92
Senior Member
 
Registered: Apr 2007
Location: Buenos Aires.
Distribution: Slackware
Posts: 3,268

Original Poster
Rep: Reputation: 49
I'm happy to see the Linux-Hardware forum honors its name. No conductive mat in this case, I've been looking better after removing old hardened grease. The fact is that the CPU top surface is metallic and that part of the cooler which is in contact with that surface is some aluminium-like mat somehow fixed to the cooler base. Furthermore, it is a bit wrinkled all over its area.

This did not pose a problem to me. I wiped both contact surfaces with isopropyl (you can read Wikipedia article on it and its amazing number of applications in the electronics field) and used a drop of silicon grease, the same used for power transistors.

Its the prettiest thing in the world to see how socket, processor, cooler and fan fit altogether with absolute perfection. Well, thanks for your posts.
 
Old 09-03-2011, 12:36 PM   #8
markhahn
LQ Newbie
 
Registered: Jan 2011
Posts: 12

Rep: Reputation: 3
sorta

the main goal in applying a thermal transfer compound is to avoid voids, so to speak. bubbles or other gaps form very effective local insulators. so when applying goo, a very effective technique is to "wet" both surfaces by applying just a smear of compound or grease, then put a blob in the center. when the surfaces are mated, parallel, the blob will spread radially and avoid bubbles. something like a hair in the goo is bad news (thought a cleanroom is not absolutely necessary

the so-called thermal pad is normally a piece of waxy phase-change material (ie "it melts"). this is very convenient for vendors. I don't know any reason why either the waxy stuff or the grease-based goo can't be reused, as long as a voidless layer is achieved.

some older types of grease-based goo actually _do_ degrade over years of heat, since they were substances like zinc oxide suspended in a thin, somewhat volatile grease. when you see hard transfer material, you want to remove and not reuse it. the waxy stuff can be reused, though I don't usually bother, since a syringe of good stuff is only a buck or two per application.
 
Old 09-03-2011, 12:54 PM   #9
cascade9
Senior Member
 
Registered: Mar 2011
Location: Brisneyland
Distribution: Debian, aptosid
Posts: 3,718

Rep: Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904
Quote:
Originally Posted by jefro View Post
Less is more in this case. You don't need to remove old grease. It doesn't go bad.
Actually, thermal paste can go 'bad'. As the paste dries out, it can slowly lose heat transferring capabilities.

Quote:
Cheap thermal compounds can dry out after a few thousand hours, which causes problems for a few reasons.

First, wet compound that's dried out won't have the density, and thus the thermal conductivity, that it had when it was wet. These compounds aren't a solution, they're a mixture; remove the liquid from them and you end up with lots of little spaces where the liquid was, which is bad.
http://www.dansdata.com/goop.htm

Last edited by cascade9; 09-03-2011 at 12:55 PM.
 
Old 09-03-2011, 01:12 PM   #10
kilgoretrout
Senior Member
 
Registered: Oct 2003
Posts: 2,333

Rep: Reputation: 143Reputation: 143
For any future readers encountering this problem, here's a link to the Arctic Silver instructions recommended by the manufacturer:

http://www.arcticsilver.com/methods.html

Arctic Silver is one of the leading brands of thermal paste for cpu/heatsink. There are others on the market and all the manufacturers have instructions on their websites. There's a lot of folklore out there regarding cpu/heatsink thermal paste but you are probably better off just following the manufacturer's instructions. Note that the instructions vary depending upon the cpu. Also, if your cpu is still under warranty, using a third party thermal paste will void your warranty.
 
Old 09-03-2011, 01:45 PM   #11
bholland2
LQ Newbie
 
Registered: Aug 2011
Distribution: Slackware, Ubuntu
Posts: 16

Rep: Reputation: Disabled
Actually, going back to the old Celeron 300 and 400 Mhz. days, there is no thermal grease necessary if you don't overclock. Yip, I remember them thar days. Intel used to ship a Celeron and a cooler and there was no thermal grease necessary, the metal to metal contact was all that was necessary to cool that CPU.

I had 2 of them, used them for about 4 years in an office environment then used them for folding@home for a couple of years till they just became so out of date and slow they just weren't worth the electricity to run them. I still have them in the basement and drag one of them up from time to time to test questionable power supplies.
 
Old 09-03-2011, 03:19 PM   #12
jefro
Guru
 
Registered: Mar 2008
Posts: 12,078

Rep: Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520Reputation: 1520
Part of the issue is what side the chip is really on. Original packages had the chip inside where many of the newer ones are on top to give direct contact with the heat sink. Thermal paste is only meant to fill the very small voids and leave direct contact with as much metal as one can. Less is more and the stuff has been silicon based as far back as I ever saw. Silicon and some metal like zinc or maybe copper in some brands.
 
Old 09-03-2011, 05:40 PM   #13
replica9000
Member
 
Registered: Jul 2006
Location: Quahog, Rhode Island
Distribution: Debian 'Sid', FreeBSD, Android
Posts: 697
Blog Entries: 2

Rep: Reputation: 125Reputation: 125
I remember building PCs where all I needed was a heatsink, no fan, and thermal compound was optional (though it usually held the heatsink in place), but this was back when 50mhz was fast!
 
Old 09-03-2011, 10:02 PM   #14
cascade9
Senior Member
 
Registered: Mar 2011
Location: Brisneyland
Distribution: Debian, aptosid
Posts: 3,718

Rep: Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904Reputation: 904
Quote:
Originally Posted by bholland2 View Post
Actually, going back to the old Celeron 300 and 400 Mhz. days, there is no thermal grease necessary if you don't overclock. Yip, I remember them thar days. Intel used to ship a Celeron and a cooler and there was no thermal grease necessary, the metal to metal contact was all that was necessary to cool that CPU.
You might have got away with no thermal grease with fairly low speed celery, but AFAIK you were still meant to use thermal grease.

Even the horrid original celeron 266 and 300 ('Covington') had thermal grease installed 'stock'. They had no L2 cache, so they ran cooler than the later cached celerons.

Quote:
Originally Posted by jefro View Post
Silicon and some metal like zinc or maybe copper in some brands.
Silicon is the most common (and cheapest), zinc oxide is around, copper I've only seen once (GeIL). Silver is pretty common now, has been for years.
 
Old 09-04-2011, 12:48 AM   #15
bholland2
LQ Newbie
 
Registered: Aug 2011
Distribution: Slackware, Ubuntu
Posts: 16

Rep: Reputation: Disabled
Actually it was the first copper Celerons that needed no grease, they just ran that cool. They came with CPU and heat sink from Intel with instructions pointing out that nothing else was needed. OEMs shipped pre-built computers that way too. The Coppermine cores ran a lot cooler than the older Mendocino cores. All older versions used aluminum conductors, the advent of copper really cooled them down. If we were still using aluminum around 1.5 to 2 Ghz would be the speed limit, copper lets us go much faster because of the reduced heat generated.

I was thinking earlier that the switch to Coppermine was at 300 or 400 Mhz, I was wrong, it was at 500 Mhz.

Heat is a matter of both speed and the manufacturing technology used. The last of the older Mendocino cores (500 Mhz)had a max dissipation of about 27 watts, the newer, faster, Coppermine cores (533 Mhz)maxed out at about 11 watts. It doesn't take much cooling to deal with only 11 watts.

Remember also that the Celeron had thermal protection built in so that if it started getting too hot it would just lower its clock till it was "thermally happy". This was never intended to be a high performance CPU.
 
1 members found this post helpful.
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
CPU fans: thermal pads and thermal paste; newbiesforever General 17 11-23-2009 11:22 PM
Problems with mounting a CPU Cooler Jubalint Linux - Hardware 3 10-11-2005 08:17 PM
Thermal paste & CPU/Heatsinks alcazar Linux - Hardware 4 02-13-2005 12:39 PM
CPU S2K bus disconnect? -> cooler fredgt Linux - Hardware 0 09-08-2004 05:03 AM
CPU cooler software FireIsMyFlag Linux - Software 1 10-09-2002 01:32 PM


All times are GMT -5. The time now is 01:25 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration