Anomalous Thermal Behavior on My MacBook Pro!

[ScarletRed]

I detected a very strange temperature behavior on my MacBook Pro. I rebooted the notebook after updating to OS X 10.4.7. Then I started browsing the net (reading up on this forum, mostly) when I noticed that the CPU temperature as reported by CoreDuo Temp was at 62±2°C. This is very unusual since I have never seen the temperature this high before. For the next 5 minutes during which the computer remained idle, I observed that the CPU temperature remained at 62±2°C. Then I let the computer go to sleep for about 60 seconds. Upon waking up, I found the core temperature to be 51°C.

For the next five minutes, I observed the temperature, again. It remained unchanged at 51±1°C during which the computer remained idle.

Then I let the notebook go to sleep for the next five minutes. It should be noted that the ambient temperature at this time was about 70°F (21°C).

At the end of five minutes, I awoke the computer and found that the CPU temperature was now reading 29-32°C. Even with light web browsing, the core temperature remained unchanged.

I repeated the test above with iStat Nano to obtain almost identical result, confirming that the anomalous thermal behavior is not due to a glitch in the temperature monitoring program.

Reason for the abnormally high idle temperature in the 60s is not known but now I know how to bring it down quickly. Just let the computer go to sleep for at least 5 minutes and resume use.

Perhaps someone with a good understanding of MacBook Pro architecture can explain this unusual thermal behavior.

 

[terriwelsh]

How can I check the core temp on my macbook?

I just got my macbook from the online store. I plugged it in and my battery only charged to 99% - and the laptop was really heating up on the left side.

Also, I ordered a 80 gig hard drive, but it says there is only 57 gigs available. How can I determine the size of the hard drive?

Thanks for any help from this brand new mac user

 

[ScarletRed]

I'm really clueless about computers but I think the first few gigabytes are used for indexing/formatting the hard drive. In addition, all those bonus softwares such as iLife, iWork, iThis, iThat,iWhatNot, and OS X will take up a lot of additional hard disk space. That explains why you have only 57 GB available.

 

[terriwelsh]

how did you find the temp?

Hi there,

How did you find the temperature of the cpu?

Thanks!

 

[ScarletRed]

Here's How...

I used a widget called iStat Nano.

 

[vv-tim]

Sounds pretty strange Scarlet... But yours seems to be a more one-time case, whereas most people with heat problems have their computer idling at 60C+ at all times -- making your computer go to sleep won't help it.

Best guess... you had a thread running that found its way into an infinite loop and was using up CPU cycles causing some heat. Putting it to sleep stopped the cycle and let the thermal sensor area cool down.

terri, you can use "System Profiler" to get info on your hard drive size, but as a poster above said, all that stuff that Apple throws onto your machine takes up quite a bit of space. To get to System Profiler go to the Apple icon in the top left and click "About This Mac" and then "More Info" in that page.

 

[terriwelsh]

hard drive size and istat nano

Hello,

As soon as I hook my mac up to the internet, I'll get istat nano. Thanks for the tip!

and as for the hard drive, I looked on system profiler, but even in "more info" I couldn't find the hard drive size.

OK, would the hard drive be called the Serial-ATA? If so, I see 74.53 gigs

Any other tips?

Thanks for all your help!

 

[ScarletRed]

Lucky Me!

Sounds pretty strange Scarlet... But yours seems to be a more one-time case, whereas most people with heat problems have their computer idling at 60C+ at all times -- making your computer go to sleep won't help it.

Best guess... you had a thread running that found its way into an infinite loop and was using up CPU cycles causing some heat. Putting it to sleep stopped the cycle and let the thermal sensor area cool down.

I guess I should consider myself very lucky for owning a MacBook Pro that normally runs at 29°C (84°F) at ambient temperature of 21°C (70°C).

 

[ScarletRed]

Hello,
and as for the hard drive, I looked on system profiler, but even in "more info" I couldn't find the hard drive size.

OK, would the hard drive be called the Serial-ATA? If so, I see 74.53 gigs

Any other tips?

Single click on MacBook HD (or whatever your hard drive is called). Then go to the upper left corner where it says Files and scroll down to Get Info. This will open up another window with the name of your hard drive at the top. If you scroll down to the General section in this window, you will see where it says Capacity: 74.53 GB. Just below that, it should say Available: 57 GB.

 

[vv-tim]

Hello,

As soon as I hook my mac up to the internet, I'll get istat nano. Thanks for the tip!

and as for the hard drive, I looked on system profiler, but even in "more info" I couldn't find the hard drive size.

OK, would the hard drive be called the Serial-ATA? If so, I see 74.53 gigs

Any other tips?

Thanks for all your help!

74.5GB is correct technically. An 80"GB" drive is based on 80 * 1000 * 1000 * 1000. A true GB is 1024 * 1024 * 1024. So if you multiply 80 * 1000 * 1000 * 1000 / 1024 / 1024 /1024 you get 74.505GB.

Hard drives are advertised using the lesser GB, whereas computer operating systems show you the "binary" GB.

The proper GB should be based on 1024.

 

[Bunsen Burner]

I guess I should consider myself very lucky for owning a MacBook Pro that normally runs at 29°C (84°F) at ambient temperature of 21°C (70°C).

Have you installed all the firmware updates? Reset the PMU? Try downloading Temperature Monitor and see what your temps are. 29ºC is incorrect.

BB

 

[generik]

Have you installed all the firmware updates? Reset the PMU? Try downloading Temperature Monitor and see what your temps are. 29ºC is incorrect.

BB

It does sound outrageously low, but hey, that is only a 25W CPU in there, not an iron...

 

[vv-tim]

I guess I should consider myself very lucky for owning a MacBook Pro that normally runs at 29°C (84°F) at ambient temperature of 21°C (70°C).

If I had to take a guess... idling at 29C is ridiculous... I'd say your thermal sensor may be busted. Mine idles at 45C -after- a thermal paste fix. It idled at 65C before the fix... so unless yours has like... water cooling or something, it shouldn't be anywhere near 29C.

 

[Bunsen Burner]

It does sound outrageously low, but hey, that is only a 25W CPU in there, not an iron...

And a Northbridge and an X1600 GPU. 29ºC is incorrect.

BB

 

[ScarletRed]

Hmmm.....

Have you installed all the firmware updates? Reset the PMU? Try downloading Temperature Monitor and see what your temps are. 29ºC is incorrect.

BB

PMU? What's a PMU?

I confirmed the idling temperature with two programs (iStat Nano and CoreCuo Temp). And yes, my laptop is up to date with the latest firmware and OS X 10.4.7.

As I am typing this, I have been browsing the net for over an hour (mostly catching up on news). As I check the CPU temperature via iStat Nano, it is reading 21-22ºC (69-72ºF). The ambient temperature at the present is 21ºC (69ºF) as reported by a widget. I am somewhat skeptical of these readings so I put my fingers directly over the heat vent just above the function keys and found it to be mildly warm (i.e. definitely warmer than 69ºF but not by much. If the exhaust temperature is mildly warm, then the CPU temperature has to be even warmer.

Suppose the temperature sensor is malfunctioning....time for me to call Apple?

 

[ncook06]

It seems to me that the update was probably quite processor intensive. I know for myself and many other users, it took quite a while. Therefore, you would not really have an "idle" reading. The computer seems to be cooling off quite quickly, and that's due to the aluminum casing and the fact that it is NOW idle (not during update or start up).

If the MBP normally feels cool, consider yourself very lucky, or consider making a donation to a poor college student like me


EDIT: My theory is not that the thermal sensor is busted, but that ScarletRed may actually have one of very very few Apple laptops in history to have the thermal paste properly applied.

 

[howesey]

74.5GB is correct technically. An 80"GB" drive is based on 80 * 1000 * 1000 * 1000. A true GB is 1024 * 1024 * 1024. So if you multiply 80 * 1000 * 1000 * 1000 / 1024 / 1024 /1024 you get 74.505GB.

Hard drives are advertised using the lesser GB, whereas computer operating systems show you the "binary" GB.

The proper GB should be based on 1024.

OS X, like Windows, measures incorrectly. The OS measures a GB incorrectly. Apple need to add an 'i' in their measurements.

vv-tim, quite a while ago, IEEE, SI and ISO bought in a new standard for quantities of bits. OS X has been slow to correct themselves. Just for your, and others, information:


8 bits to a byte
1000 bytes = 1kB
1000 kB = 1 MB
1000 MB = 1 GB

8 bits to a byte
1024 bytes = 1 kiB
1024 kiB = 1 MiB
1024 MiB = 1 GiB

Please note the 'i', which represents 10 power 2 or binary.

The proper GB should be based on 1024.

1024MB to GB as you stated is incorrect.

 

[Bunsen Burner]

PMU? What's a PMU?

Power Management Unit. Turn off the machine, unplug it and pull the battery. Press and hold the power button for at least five seconds. Reinsert the battery, plug back into AC and boot the laptop.

BB

 

[ScarletRed]

The intended purpose of your instruction isn't clear.....

Power Management Unit. Turn off the machine, unplug it and pull the battery. Press and hold the power button for at least five seconds. Reinsert the battery, plug back into AC and boot the laptop.

BB

...to what end? Will this 'fix' the anomalous temperature of my MBP?

 

[Bunsen Burner]

...to what end?

To reset it.

BB

 

[vv-tim]

OS X, like Windows, measures incorrectly. The OS measures a GB incorrectly. Apple need to add an 'i' in their measurements.

vv-tim, quite a while ago, IEEE, SI and ISO bought in a new standard for quantities of bits. OS X has been slow to correct themselves. Just for your, and others, information:


8 bits to a byte
1000 bytes = 1kB
1000 kB = 1 MB
1000 MB = 1 GB

8 bits to a byte
1024 bytes = 1 kiB
1024 kiB = 1 MiB
1024 MiB = 1 GiB

Please note the 'i', which represents 10 power 2 or binary.


1024MB to GB as you stated is incorrect.

Strange... someone should tell Western Digital that.

Not that I ever claimed a GB was 1024MB (as there is of course discrepancy over that unit as well). I said a Kilobyte was 1024 bytes. A GB is 2^30. That's 1,073,741,824 bytes. The IEC "recommends" calling it the GiB, but the 2^30 value of the GB was the original value used in computer memory sizes.

I doubt Windows and OS X plan on "correcting themselves" because they're not wrong. Linux is updated all the time and reads the same way.

 

[Counterfit]

74.5GB is correct technically. An 80"GB" drive is based on 80 * 1000 * 1000 * 1000. A true GB is 1024 * 1024 * 1024. So if you multiply 80 * 1000 * 1000 * 1000 / 1024 / 1024 /1024 you get 74.505GB.

Hard drives are advertised using the lesser GB, whereas computer operating systems show you the "binary" GB.

The proper GB should be based on 1024.

Technically, 1024^3 (2^30) is a Gibibyte

 

[JurgenWigg]

I'm really clueless about computers but I think the first few gigabytes are used for indexing/formatting the hard drive. In addition, all those bonus softwares such as iLife, iWork, iThis, iThat,iWhatNot, and OS X will take up a lot of additional hard disk space. That explains why you have only 57 GB available.

Plus formatting the drive, it's not actually 80 gb to start.

Edit: Whoops didnt read all the way down

 

[howesey]

Plus formatting the drive, it's not actually 80 gb to start.

Edit: Whoops didnt read all the way down

Depends on how it has been formatted.

Good old classic that confused people. Floppy disc, FAT16 can have 1.44MB, whereas ADFS had 1.6MB after format.



As for WD, every hard drive I have bought from them for the last few years clearly states that they measure a GB as 1000 of xxxx. My IBM drives are the same. Where that lawsuit comes from I do not know. Perhaps it has been enforced in EU/UK for a while.

As far as I know, using Red Hat, Mandrake and Debian all say kiB and MiB when you view folder/file properties.

 

[vv-tim]

Technically, 1024^3 (2^30) is a Gibibyte

Thank you for actually reading the discussion No, it's NOT a Gibibyte. That's simply the proposed term for it.