MPBs and XP - careful with the heat

MacDoc · Apr 13th, 2006, 05:56 PM

	Quote:
	We continue to report on an issue where MacBook Pros appear to run significantly hotter when booted into Windows XP than when booted into Mac OS X. MacFixIt reader Charlie writes: "My MacBook Pro gets so hot when running windows you almost can't keep you hand on the hottest spots." Meanwhile, MacFixIt reader David Hannon took some surface temperature measurements. He writes: "I can confirm that the MacBook Pro run much hotter under Windwos XP. "After reading through MacFixIt, yesterday I did the Boot Camp install and installed Windows XP Home Edition. "I have one of those infra-red thermometer guns that digitally reads surface temperatures. My MacBook Pro 2.16 GHz was resting on an X-pad cooling pad, so there was some air circulation underneath. "After the MacBook Pro had been running OS X for about an hour, I did a temp scan of the underside. Across the rear sections near the hinge, i recorded temperature readings varying from 109 degrees F to 112 degrees F. The hottest being in the center of the laptop. "After doing the complete install of Windows XP and running that for about an hour I did another temperature scan of the underside. This time the readings varied from 118 degrees F to 121 degrees F. The hottest area again being under the central rear area. These readings are again with the MacBook Pro having sat on a X-pad cooling pad. I can assume that they would get even higher if the laptop was flat on a table surface. I also noticed that the cooling fans were working more than when booted into Mac OS X 10.4.6. In order to reduce overall temperature, make sure your MacBook pro is seated on a hard surface with under-unit ventilation.

http://www.macfixit.com/

Good advice - we noticed it too when we had to do a full XP set up on a 1.83. Likely worse on the faster processors and those with hotter drives.

Does not seem to bother the iMacs - better cooling.

Apple101 · Apr 13th, 2006, 10:31 PM

	Quote:			Originally Posted by MacDoc
	http://www.macfixit.com/ Good advice - we noticed it too when we had to do a full XP set up on a 1.83. Likely worse on the faster processors and those with hotter drives. Does not seem to bother the iMacs - better cooling.

I would not be worried about it all. Why? Because the MBP employs an ATPM (Advanced Thermal and Power Management) system which is governed by the system management unit, and the thermal management software within the operating system. So what's your point? Well in the MBP there are thermal sensors attached to the bottom case, and to the heat sink. They on a consistent basis monitor and communicate with the operating systems thermal software and the system management unit adjusts fan operation according to the conditions being monitored in real time.
How the ATPM is governed depends on the operating system. It is obvious that Windows XP has a different way of monitoring thermal and power conditions.

In short your laptop will not melt or overheat to the point were it will explode as this is simply impossible. Mainly because for example if the operating system that is being used does not manage the thermal conditions then the system management unit will begin to rev the fans at full speed because they are at an unmanaged state. Also if the system temperature exceeds normal operation temperatures then the system will begin to ramp up fan speeds, if the operating temperature continues to escalate then the management unit will call for a system shutdown.

MacDoc · Apr 13th, 2006, 11:06 PM

Might be a worthwhile add on.

But the reality is there may not be enough fan throughput to keep the machine cooled properly - Apple has had issues with this in the past and clearly Apple is not engineering any software control in for XP so the warning is well heeded.

The fans do not come on yet the machine can get very hot.
For instance doing a full software install including all the apps and updates - because the OS is on the installer the heat controls are not active.

Now a G5 tower will by default spin the fans up when no controls are present but the MBP appears not to do the same thing....so it gets bloody hot.
It's fine to quote theory - but I've just done 4 of these in the past couple of days and I'll attest.

a) they are HOT and this was on a glass desk. I was shocked even touching the desk surface underneath.

b) the fans do not come on during long installs indicating it's software controlled not integral to the hardware.

TANSTAAFL - even tho Intels do run cool for the power even the G4s got hot and now you have fast ram, fast main bus, fast video card and a two core processor with a giNormous cache to cool....all those things make it go fast.
All those things make it hot. ( I mean look at the size of that honkin' power supply for the unit ).
Note that Apple does not consider the unit a "laptop".

I suspect the Macbook will be aluminum just for additional radiation cooling. The faster G4 iBooks tended to cook their drives one reason I would NOT opt for a 7200 in these.

I think there IS a shutdown thermal sensor and that is what is causing the unexpected machine shut downs.

The MacBooks are brilliant, worth every penny and not quite perfect. A bit of heat management is in order.

Apple101 · Apr 13th, 2006, 11:29 PM

	Quote:			Originally Posted by MacDoc
	The fans do not come on yet the machine can get very hot. For instance doing a full software install including all the apps and updates - because the OS is on the installer the heat controls are not active. b) the fans do not come on during long installs indicating it's software controlled not integral to the hardware. I suspect the Macbook will be aluminum just for additional radiation cooling. The faster G4 iBooks tended to cook their drives one reason I would NOT opt for a 7200 in these. I think there IS a shutdown thermal sensor and that is what is causing the unexpected machine shut downs.

If the fans do not come on then there might be a problem with the system. I have worked on the MacBook Pros as well and there were a few complaining about the heat, however according to the tests conducted the system was functioning correctly. The fans operated at normal speeds during processor intensive tasks, the thermal conditions, considering the type of system was normal.

The thermal and power conditions are monitored and controlled with both hardware and software NOT just software.

Also there is no thermal shutdown sensor (technically). I have access to certain information that confirms that there are thermal sensors attached to the bottom of the case and the heat sink. As mentioned above they on a consistent basis monitor and communicate with the operating systems thermal software and the system management unit adjusts fan operation according to the conditions being monitored in real time. I am not authorized to share certain information with you however if you are in Apples Authorized service network then you can see for your self.
Also I seem to doubt that Apple will release an aluminum MacBook as it would significantly drive its cost up.

MacDoc · Apr 13th, 2006, 11:40 PM

You are talking when the OS is operant which it is not when doing system installs or XP.
Apple is tweaking these - Rev D already.
They are STILL worth it - just a bit of heat management is recommended especially with XP.

Remember all our machines go out with a full RAM load and fast RAM adds heat and power draw.

We are now doing full blown installs right from scratch on all the MBPs to see how individual units handle heat.

All that said they are glorious machines.

Apple101 · Apr 13th, 2006, 11:50 PM

	Quote:			Originally Posted by MacDoc
	You are talking when the OS is operant which it is not when doing system installs or XP. Apple is tweaking these - Rev D already. They are STILL worth it - just a bit of heat management is recommended especially with XP. Remember all our machines go out with a full RAM load and fast RAM adds heat and power draw. We are now doing full blown installs right from scratch on all the MBPs to see how individual units handle heat. All that said they are glorious machines.

Thermal management is provided during and after setup. As long as OS X is booted thermal management is provided. However with Windows XP thermal management is not provided during the initial setup, but when fully booted thermal management is available (according to Microsoft)
I do agree with you that they are gorgeous machines! No doubt about that!

MacDoc · Apr 13th, 2006, 11:54 PM

I don't think there is any thermal management in the install discs.

Apple101 · Apr 13th, 2006, 11:58 PM

	Quote:			Originally Posted by MacDoc
	I don't think there is any thermal management in the install discs.

With OS X as long as its booted (it doesn't matter if it is an install or not) thermal management is provided. However with Windows XP you are correct, thermal management is not provided during the initial setup, but once booted thermal management is provided.

contoursvt · Apr 14th, 2006, 11:29 AM

	Quote:			Originally Posted by Apple101
	With OS X as long as its booted (it doesn't matter if it is an install or not) thermal management is provided. However with Windows XP you are correct, thermal management is not provided during the initial setup, but once booted thermal management is provided.

XP doesnt have thermal management. The only thing they have is the halt instruction which helps somewhat when the computer is idle or not under heavy loads. This has been around since NT4. Microsoft provides no monitoring of fans or voltages. When running XP, the system should be running the fans at what ever speed the system board tells it to run. Just imagine how many PC manufacturers there are and how many stores building machines with all kinds of parts. There is no way Microsoft will be able to manage anything much. In PC world, the board maker is the one that provides the management and the same would hold true with XP running on a mac.