thermal grease - my experiences

spoem

macrumors newbie
Original poster
Jun 16, 2006
3
0
I recently got a week 17 2.16ghz MBP.

Note - this is with updated SMC firmware.

When I recieved it, I noticed it was hot, so I loaded up Speedit, and fired up 2 x yes > /dev/null.

The temp on the cpu started going up quickly. The base of the laptop became very hot and the area above the F keys.

Tee noticed the fans only came on when the cpu got to 65 degrees, and then it levelled out at 74-75C.

Even then, the fans weren't on very strong and the bottom of the case was blistering hot.

Over this weekend, I had to open the box up to change the hard disk, so I figured that while I was in there, I'd swap the thermal greese for arctic silver5. got rid of the old dried out goop apple were using and applied a small amount of AS5.

Now, when I run the same yes > /dev/null test, I see the following:

CPU heat up rapidly, but the bottom of the case doesn't get hot unless you leave the CPU running at full for more than 30 minutes.

THe fans come on now when the cpu is at 45 C and the cpu doesn't get past 65C.

The whole time though, the laptop was on my legs and wasn't burning like it was before!

Under normal usage patterns, the bottom the case doesn't get more than luke warm the cpu never breaks 47 degrees (even with say itunes playing with visualization).
 

Core Trio

macrumors regular
May 16, 2006
175
0
New Jersey
While thats awesome that it worked out for you and everything, I really wish people would post pictures before and after of their temperature readings so we could all see how effective this really is. B/c as we all know, different people have had diffrent results.
 

spoem

macrumors newbie
Original poster
Jun 16, 2006
3
0
Core Trio said:
While thats awesome that it worked out for you and everything, I really wish people would post pictures before and after of their temperature readings so we could all see how effective this really is. B/c as we all know, different people have had diffrent results.
The CPU core temp is misleading as the cpu is obviously meant to run hot, as long as that's heat is going somewhere.

I feel rocks if the CPU is running at 70C as long as it's not burning my legs.

.. and it's not now (although it's not gonig above 65).
 

Pressure

macrumors 601
May 30, 2006
4,007
269
Denmark
spoem said:
The CPU core temp is misleading as the cpu is obviously meant to run hot, as long as that's heat is going somewhere.

I feel rocks if the CPU is running at 70C as long as it's not burning my legs.

.. and it's not now (although it's not gonig above 65).
In other words, you fans are turning on more now than before?
 

Core Trio

macrumors regular
May 16, 2006
175
0
New Jersey
i would be so afraid to do this myself for fear of breaking something and voiding my warranty

EDIT: if you successfully replace the grease and then say a year later something goes wrong with the laptop, completely unrelated to the thermal grease you replaced, would applecare still cover it??
 

Spectrum

macrumors 65816
Mar 23, 2005
1,471
783
Never quite sure
I thought someone had suggested that the fans coming on more was a consequence of not correctly reattaching some sensor on the heat-pipe during reassembly - and not necessarily due to the application of the thermal grease.
 

vv-tim

macrumors 6502
May 24, 2006
366
0
Spectrum said:
I thought someone had suggested that the fans coming on more was a consequence of not correctly reattaching some sensor on the heat-pipe during reassembly - and not necessarily due to the application of the thermal grease.
That's incorrect. The fans will be on full speed ALL THE TIME if you don't reattach the thermal sensor.

To the post above that one... Now, I can't promise you that they'll honor the warranty... but if something else breaks (LCD, battery, etc) completely unrelated to the thermal paste, I doubt they'll even tear apart the computer to check to see if your thermal paste is [badly applied].
 

Egosphere

macrumors member
Apr 21, 2006
69
0
spoem said:
THe fans come on now when the cpu is at 45 C and the cpu doesn't get past 65C.
I am very glad to hear your results were so good, but I am having trouble understanding the above. So, the fans turn on when the CPU is at a lower temperature? That's weird. Unless, of course, if the fans are controlled by a different thermometer. Like, the fans are controlled by the heat in the heat pipes and now that the heat is actually directed efficiently to and through the heat pipes (without the Apple goop directing the heat everywhere--as I understand it), the fans work when the heat pipes are hotter and they are because they catch the heat like they should. If it's not like this, and the fans are controlled by the CPU temp sensor, then I don't understand how this could be. Can you explain this please? Or try to.
Again, I'm very pleased to hear how well replacing the grease worked for your MBP.
 

vv-tim

macrumors 6502
May 24, 2006
366
0
Egosphere said:
I am very glad to hear your results were so good, but I am having trouble understanding the above. So, the fans turn on when the CPU is at a lower temperature? That's weird. Unless, of course, if the fans are controlled by a different thermometer. Like, the fans are controlled by the heat in the heat pipes and now that the heat is actually directed efficiently to and through the heat pipes (without the Apple goop directing the heat everywhere--as I understand it), the fans work when the heat pipes are hotter and they are because they catch the heat like they should. If it's not like this, and the fans are controlled by the CPU temp sensor, then I don't understand how this could be. Can you explain this please? Or try to.
Again, I'm very pleased to hear how well replacing the grease worked for your MBP.
Yes, the thermal sensors are more accurate now due to the proper heat transfer to the heat pipe.
 

CanadaRAM

macrumors G5
Pressure said:
In other words, you fans are turning on more now than before?
Yes, my guess is that this is a consequence of the heat sink transmitting the heat away from the CPU more effectively. The fans are on, dispersing the heat energy that formerly was not being passed into the heatsink and therefore was being transmitted through the bottom of the case.