Welcome to the MacNN Forums.

phantomo · Apr 19, 2006, 11:07 PM

When my PowerBook 12" gets hot, I know the fan is running because I can feel hot air coming out from the hinge area. Now using the MBP, I can't feel hot air coming out at all even the MBP gets hot. Is this normal?

I can hear very low noise, perhaps it is the fan but I am not sure because the PB 12" is louder and I can tell when the fan is on.

mduell · Apr 19, 2006, 11:44 PM

If you can't hear it, does it matter?

Try stuffing the laptop under a comforter while it's running at 100% CPU... I think you'll hear the fans rev up.

Simon · Apr 20, 2006, 02:49 AM

When the MBP revs up its fans you can definitely hear it unless you're using it in a sawmill or something. If you can't hear them rev up, they're not on. If you hear a faint and constant whirr, that's the HDD. My 7200rpm 100GB MBP HDD is definitely louder than the 5400rpm 80GB HDD I have in my 1.67GHz PB G4.

onlykaria · Apr 20, 2006, 04:10 AM

Originally Posted by Simon

When the MBP revs up its fans you can definitely hear it unless you're using it in a sawmill or something. If you can't hear them rev up, they're not on. If you hear a faint and constant whirr, that's the HDD. My 7200rpm 100GB MBP HDD is definitely louder than the 5400rpm 80GB HDD I have in my 1.67GHz PB G4.

wow!!

ok, this would mean that my fan is never on???

hmmm

i would like though the option to turn the fan on or up more because this thing gets hot and stays hot. i honestly do wonder if the fan ever does go on.

Simon · Apr 20, 2006, 07:30 AM

Originally Posted by onlykaria

ok, this would mean that my fan is never on???

Well, my MBP 2.0 only turns on the fan when you really tax the CPU for a while. And it also depends on what surface the MBP is being used on. A lap or bed will make it heat up much faster than a solid table or marble surface.

Try iTunes visuals to get the CPU to do some work. Let it run for a while and the fans should eventually rev up. That is of course unless you live in Greenland...

phantomo · May 3, 2006, 10:44 AM

I did try having the CPU to run at almost full load for an extended period of time, the bottom of the MBP is too hot to touch and I still couldn't hear the fan turns on. It is for sure hotter then the 12" PB I have. I am starting to believe the thermal grease issue...

Hopefully Apple will provide a fix.

quilmes · May 4, 2006, 11:41 AM

any programs that can show if the fan is moving?

eevyl · May 4, 2006, 11:49 AM

The MBP 15" fans are way quieter than my previous PowerBook G4 12" ones, but I can definitely hear them if I max the CPU, try playing a couple or three HD trailers at once, mute the volume, the fans should definitely kick in louder.

quilmes · May 4, 2006, 11:51 AM

my fans never run. only when i turn on.

phantomo · May 5, 2006, 08:48 AM

eevyl, when the fans are on, is there hot air coming out from the hinge area? I tried your 3 HD trailer test to max out the CPU but.... QT quit during play.

My MBP is so hot that I couldn't touch the bottom after normal use for about 10 minutes.

jasonsRX7 · May 5, 2006, 09:19 AM

How to tell if the fans are running: set it on your lap. If your skin blisters within 1 minute, the fans are not running. If 3rd degree burns only occur after 2 or more minutes, the fans are running and the system is being optimally cooled. Remember, heat is not a problem, but fan noise is.

eevyl · May 5, 2006, 09:56 AM

Well, I had those crashes with a lot of HD trailers at once, try one at 720p and one at 1080p, that should work at nearly maxing the CPU.

aristobrat · May 5, 2006, 10:12 AM

Originally Posted by phantomo

I tried your 3 HD trailer test to max out the CPU but.... QT quit during play.

FWIW, if you open up the terminal and type yes (and hit return), it'll max out your CPU too.

eevyl · May 5, 2006, 10:49 AM

Actually, you need two terminal windows with yes to max out both cores. And even then I was not able to heat up the CPU as high as 80 without playing a HD trailer and both yes processes. The trailer didn't skip frames btw ^_^

aristobrat · May 5, 2006, 12:50 PM

Hmmm. I'll have to play around with YES some more. When I was dinking with it earlier, one instance of it maxed out both of my CPUs, but I only ran it for 10-15 seconds.

polendo · May 5, 2006, 02:15 PM

If you have windows installed.. download Pc Wizard.. it shows the revs the fan is running.

I wouldn't be that concerned about it..if the fan was failing you would probably be experiencing some re-starting. I just think your book hasn't gotten to the point were it needs the extra revs of the fan. If you want to try something weird, go to a clinic and ask a doctor to borrow his/hers things that can hear the heart and so on.. should be able to hear the fan! haha

phantomo · May 5, 2006, 09:43 PM

eevyl, thanks, I've tried playing 2 1080 HDtrailers and that how it quit Quicktime.

jasonRX7, heat is a problem if fan is not running. So far, I've keep checking my unit while using and it is extremely hot even compare to the 12" PB which is famous for it heat.

I work this MBP in an quiet environment, I never hear the fan running even it is under full load for 10 minutes and the bottom side just burns.

I will use a themometer and do some measurement as empirical data.

sllowry · May 6, 2006, 04:28 AM

phantomo, instead of using a real thermometer, you may try the "Temperature Monitor" widget which shows how hot your MBP gets.

When I start my MBP, it's about 20 degrees Celcius, then quickly it goes way up to about 43C. So far that's the average highs, and I'm hating it.

Simon · May 6, 2006, 05:09 AM

AFAIK TM and TM widget don't work with the MBP (on mine TM only sees the HDD's sensor). That's why everybody is using thermometers.

eevyl · May 6, 2006, 07:29 AM

Yup, Temperature Monitor only reads the hard disk temp sensor of the MBPs. The only way to measure the chip in die sensor is to use http://speedit.increw.org/

phantomo · May 8, 2006, 05:08 AM

I've downloaded this: http://macbricol.free.fr/coreduotemp/ Because it is based on speedit, it will show the CPU temperature.

While playing 1080 HD Superman Trailer 2, my cpu went up to 72 deg C. (My MBP is on the desk and ambient temperature is ~23 deg C).

Simon · May 8, 2006, 09:02 AM

Using CoreDuoTemp I get roughly 60C when idle and up to 72C when playing MoHAA. This is with a MBP 2.0GHz on a wooden table at roughly 20C room temp.

mark.s · May 8, 2006, 12:55 PM

All the discussions about temperature had me worried, so I decided to do some testing on my MBP.... here are the details:

MBP 2.0Ghz 2GB RAM 120GB 5400 256MB X1600 serial W8616 (got it a week and a half ago).

I've got no whine problems and the screen is great (no stuck or dead pixels, no dodgy backlighting etc). When the lid is closed I get a millimeter or two of gap on each side of the screen, but for me that doesn't warrant a return (especially considering the luck I had with the screen).

Running on AC, with a wireless connection, using CoreDuoTemp I get the following:

idling after startup in the first minute or two - 44C

100% cpu (2 x yes > /dev/null):

- 1 min 70C
- 2 min 77C
- 3 min 81C

(the fan then comes on, so I'm assuming that it kicks in at 80C - I hear the fan on the lefthand side, very faint sounds like a whining engine - normally all I hear is the 'whoosh' of the drive)

- 4 min 79C
- 5 min 78C
- 10 min 79C

(the fan stays on, and it stabilizes here and stays below 80C)

Stopping the two terminal processes I get the following:

- 1 min: 63C
- 3 min: 59C
- 10 min: 54C

When the processor is maxxed out, the left underside and the bar above the keyboard get hot. They are not hot enogh to burn.... I can keep my fingers pressed up against the metal without any problems, although it's not exactly comfortable.

So... not sure whether anything changed with the later models, or whether I am just lucky, but these values seem OK to me, compared to values I've seen on the net stating 95C values under load!

phantomo · May 11, 2006, 01:23 AM

marks.s, thanks you for your input. I've testing the MBP with the same procedure you provide and I am getting similar results except the full load temperature maintain at aorund 75-76 deg C. This is probably due to the 1.83GHz CPU instead of your 2.0GHz.

I finally hear the fan kicks in at around 80 deg C, it is very very faint sounds as you said. Thanks again.

But I do hope it is cooler on the case because there is no way I can use this on my lap.

Simon · May 11, 2006, 03:07 AM

I did the same test mark.s did with my 2.0GHz MBP (running in closed-lid mode on a wooden table).

After launching 2x yes > /dev/null (CPU usage went to 100%) my temp reached 85C until the fans kicked in. The temp stabilized at 83C within a minute or two. After stopping the the two yes processes, I get 63C within 1 minute and the fans stop. The temp stabilizes at 63C.

n8236 · May 17, 2006, 12:26 AM

I have very similar results as Mark as well, 53*C @ near idle for about 10 mins.

My max temp was 85*C (@ full load, but once the fans kicked in it settled from 79-82*C.

I've read many posts where the max load was in the low to mid 70s, and I think if mine could reach that temp, I would be happy. I use my laptop in my bed b4 sleep and the high temp easily penetrates through my down blanket. lol