[Grizzly Adams]

First of all here's my principal source:

ftp://download.intel.com/design/mobi...s/30922102.pdf

The build up:

According to the above the dual core shuts off at 125°C (not new to forum regulars but pls bare with me) maximum advised operating temperature of 100°C (also not new) however the above document also states the CPU as being under "sleep power" mode and producing 50°C (not far off some many of the Macbook idle readings) - though it does have a "deep sleep" power mode which apparently pumps out 35°C.

This 100°C maximum is much higher than say the AMD 64's (and most other CPU manufacturers) maximum of around 70-75°C, though the Pentium M had a maximum of 100°C (only other processor I found to with a max temp this high) and I don't remember them getting that hot.

What this tells us is that the CPU is perfectly able to cope under these temperatures, and suggest an idle temperature of about 25-30°C above the average processor.

Now here's the drop:

The fans are pretty much off in idle mode.....
When things get a bit toastier we can definitely hear the fans kick in (though still not too powerful).....

So.... if the fans do kick in when things start getting really rather hot how could it possibly be the thermal past?

I mean if the thermal paste were causing the CPU to overheat the temperature censor which is built into the CPU would still provide accurate readings and therefore cause the fans to kick in at the "specified" lower temperature set by Apple (which apparently cannot be obtained due to thermal paste insulation causing heat to be trapped), and they would not stop going until the temperature was lowered to that level -i.e. NEVER - due to the thermal paste.

The very fact the fans stop proves that the thermal paste isn't the issue - even if the heat isn't even coming from the CPU area (center under keyboard) but is instead coming from the top left (keyboard side).

So if we can't hear the fans at all at the lower end of the macbook temperature range then the CPU can't be getting any hotter than Apple anticipated or programmed their machines for.

However this still doesn't calm my fears about the heat and any patch that makes the fans come on even earlier will be eagerly awaited by me, I just hope I don't leave the house with the laptop on and come back to a burned out house - you reckon Apple would cover that?

[money69]

Well, I like probably alot of people have ordered a Macbook, I am waiting for it to show up this week, I went to the Apple store here in Houston today and looked at the Macbooks to tide me over from when I am expecting mine and I made a point to feel in the top left on the underside of the laptop, it was warm no doubt but nothing that seemed dangerously warm to me, would I use it on my lap? Probably not, but I wouldnt generally use my laptop like that anyway, I guess Ill have to wait and see how things turn out.

[yticolev]

Was it necessary to start another thread for this? Did you read the other threads? If you had, you would find out that changing the thermal paste has actually fixed this issue for many. The reason it that the thermal paste prevented heat from entering the heat pipe, which is where the sensors are for the fans. No entry of heat, no fan action.

[Simon]

Originally Posted by yticolev

If you had, you would find out that changing the thermal paste has actually fixed this issue for many.

You're being selective. There are also reports that it hasn't substantially changed anything for others. This topic is far from over.

[Grizzly Adams]

Originally Posted by yticolev

The reason it that the thermal paste prevented heat from entering the heat pipe, which is where the sensors are for the fans. No entry of heat, no fan action.

It is true that much of this information is in other threads, I just thought it would be useful to collect it and tidy it up a bit.

Agreed: No entry of heat, no fan action. - The sensors would not register the increase in temperature and therefore not start the fans. - Not rocket science...

But surely if this was the case CoreDuoTemp would not show the correct (and extremely high) reading either. - Also not rocket science...

It cannot be that the sensors' readings are too low, to me the only feasable explanation is that running hot was intentional - the levels of heat reached when really pushing the machine are, however, another issue altogether...

[Grizzly Adams]

Check this out, very very interesting mini article, explains a lot about the hugely varying heat/noise results we've been seeing post re-application of the thermal paste....

http://gizmodo.com/gadgets/laptops/t...ues-176172.php