Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Notebooks > How hot is too hot?

How hot is too hot?
Thread Tools
Mac Elite
Join Date: Oct 2000
Status: Offline
Reply With Quote
Aug 3, 2007, 04:10 AM
 
I'm wondering what the acceptable heat levels are for laptops. According to iStat Pro, when I'm import a DVD using Handbrake, my new 2.2 MBP gets up to 78 degrees Celsius in "CPU A" while the "GPU Diode" gets up to 76 degrees. Both fans are running full-tilt. Now, I realize importing one of my DVDs to play in iTunes is fairly taxing on the system, which is why I was wondering whether these are normal levels of heat or whether I might be having any issues with too much thermal paste? Even in light-use, I find the left side of my MBP gets a lot hotter than my 1GHz PowerBook ever did or any of the MacBooks that I've used.

(Having said that, this is a fantastic machine!)
     
Posting Junkie
Join Date: Nov 2000
Location: in front of my Mac
Status: Offline
Reply With Quote
Aug 3, 2007, 07:11 AM
 
78C under load for a 2.2 GHz C2D is nothing unusual. The CPU is spec'ed to work normally up to 100C. The 8600M GT GPU on the MBP can get fairly hot as well. It's not surprising to see it at 76C. As long as both fans are working, the heat will be removed from the CPU, GPU, and chipset.

These temps are nothing to worry about. The real issue is if your MBP is still comfortable to use. The case can become fairly warm and if your not comfortable with its temperature you can manually crank up the fans to reduce the internal temps of your MBP. A simple and free utility to do that is smcFanControl.
     
Moderator
Join Date: Feb 2006
Location: on the verge of insanity
Status: Offline
Reply With Quote
Aug 3, 2007, 06:45 PM
 
I've been using smcFanControl on my 2.4. If I'm just doing normal surfing, etc., I leave it at 2000 rpm. If I am going to do something under load, like play a game, I'll up it to 4000 rpm.
I like my water with hops, malt, hops, yeast, and hops.
     
Posting Junkie
Join Date: Oct 2005
Location: Houston, TX
Status: Offline
Reply With Quote
Aug 3, 2007, 07:21 PM
 
85C is the point at which the chipset will start underclocking the CPU to cool it, and it won't shut down to protect itself until 125C, so you're just fine in the high 70s.
     
Senior User
Join Date: Dec 2005
Status: Offline
Reply With Quote
Aug 3, 2007, 07:39 PM
 
Originally Posted by Simon View Post
These temps are nothing to worry about. The real issue is if your MBP is still comfortable to use. The case can become fairly warm and if your not comfortable with its temperature you can manually crank up the fans to reduce the internal temps of your MBP.
Yes agreed. I think people are worrying about the wrong problem when it comes to hot MBPs because the computer can handle it...but can you? It's more about a person's comfort rather than damaging the computer. I've noticed that my desktop runs a lot warmer than my laptop but I'm not phsyically touching my desktop so heat does become more important on a laptop even if you are not placing it on your lap as some people keep pointing out.

On a hot day the surface of my PowerBook can become rather warm and borders on being uncomfortable to type on. My laptop averages 40c so 78c sounds very uncomfortable to me. I never worried about the heat damaging my computer though.
     
Posting Junkie
Join Date: Nov 2000
Location: in front of my Mac
Status: Offline
Reply With Quote
Aug 4, 2007, 03:31 AM
 
Originally Posted by EndlessMac View Post
My laptop averages 40c so 78c sounds very uncomfortable to me.
Well the 78C are measured at the CPU. Obviously the case will be a lot less. Your comfort depends on the case temperature and not the CPU temp. If thermal transport works well even a 78C CPU doesn't have to be uncomfortable. If it is, crank up the fans and you should be fine.
     
Senior User
Join Date: Dec 2005
Status: Offline
Reply With Quote
Aug 4, 2007, 12:23 PM
 
Originally Posted by Simon View Post
Well the 78C are measured at the CPU. Obviously the case will be a lot less. Your comfort depends on the case temperature and not the CPU temp. If thermal transport works well even a 78C CPU doesn't have to be uncomfortable.
The 40c rating on my PowerBook is also measured at the CPU and on hot days it goes up to maybe 50c max, but even that temperature feels a little too warm on the case so I was assuming that the 78c MBP would be hotter.

If the MBP is able to disperse that heat before it reaches the case's top surface that all the better. My original point was similar to yours in that people should be less worried about the CPU temperature and worry more about whether the surface temperature is too uncomfortable to use.

Some people think the heat will damage their computers when that's really not something they need to worry about. It's more about whether the heat makes them uncomfortable, and I agree they should use smcFanControl or something to help fix the problem.
     
Posting Junkie
Join Date: Nov 2000
Location: in front of my Mac
Status: Offline
Reply With Quote
Aug 5, 2007, 05:20 AM
 
The C2D in a MBP certainly gets hotter than the G4 used in a PB. OTOH the MBP cooling system has been improved significantly. So just comparing CPU temperatures can give a wrong impression. That said, under load my 2.33 GHz MBP's case is still slightly warmer than my 1.67 GHz PB's.
     
Fresh-Faced Recruit
Join Date: May 2005
Location: Southern CA
Status: Offline
Reply With Quote
Aug 5, 2007, 04:00 PM
 
I have been following this thread. Here's what I did.

I sent my too hot MacBook Pro in to Apple, and the replaced the motherboard. I am grateful to have AppleCare.

When the MacBook Pro came back, after brain surgery, I adjusted the energy savings preference, to lower performance, both a/c and battery.

And I downloaded the recommended freeware program, "Fan Control", and adjust the speed of the fans, to a faster setting.

Lobotomo Software: MoofMenu


joegomolski
     
Fresh-Faced Recruit
Join Date: Aug 2007
Status: Offline
Reply With Quote
Aug 6, 2007, 12:50 PM
 
Originally Posted by joegomolski View Post
I have been following this thread. Here's what I did.

I sent my too hot MacBook Pro in to Apple, and the replaced the motherboard. I am grateful to have AppleCare.

When the MacBook Pro came back, after brain surgery, I adjusted the energy savings preference, to lower performance, both a/c and battery.

And I downloaded the recommended freeware program, "Fan Control", and adjust the speed of the fans, to a faster setting.

Lobotomo Software: MoofMenu


joegomolski
So, did they give you any trouble when you wanted it fixed? Did the brain surgery actually help, or did you have to run fan control and lower the display brightness because it was still hot?

Just wondering, I have a 15.4" 2.2Ghz MBP that I just picked up last week. I have also noted the high temps, mine has hit 76 deg C a couple times, at which time the fans jumped to 6K RPM. Like others have said it becomes hot to the touch. It is also my first laptop and this is really the only issue I have with the machine.

Thanks,
J
     
   
Thread Tools
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Top
Privacy Policy
All times are GMT -4. The time now is 06:54 PM.
All contents of these forums © 1995-2015 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2015, Jelsoft Enterprises Ltd., Content Relevant URLs by vBSEO 3.3.2