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-   -   C2D MBP much cooler than CD MBP - so how did they do it? (http://forums.macnn.com/69/mac-notebooks/316542/c2d-mbp-much-cooler-than-cd/)

 
Simon Nov 8, 2006 03:27 AM
C2D MBP much cooler than CD MBP - so how did they do it?
As soon as I received my 2.33 GHz C2D MBP I noticed that its case feels a lot cooler than my original rev A 2.0 GHz CD MBP. The warmest area is still on the underside but whereas on the CD MBP the upper side of the case always felt pretty warm (and the part between F keys and screen got really hot), the upper side of my C2D MBP is about room temperature.

So I took an infrared thermometer just to make sure I wasn't kidding myself. Both were on the same table and both were running the same stuff. Indeed the palm rest areas of the new MBP are on average about 15C/27F cooler.

I also ran smcFanControl and noticed that the C2D's minimum fan speed is set by Apple to 2000 rpm (fortunately it's still dead quiet :thumbsup: ) whereas the CD MBP's fans have a minimum of 1000 rpm. But is that enough to make a difference? No. When I set the CD's fans to 2000 rpm minimum speed the surface temp didn't change significantly, even after hours of use.

My CD MBP (an early model) is getting a new logic board soon anyway and I'm anxious to see if that changes anything, but even if it does I doubt it will be as much as 15C/27F. And since the TDP of the new 2.33 GHz C2D is certainly not lower than the 2.0 GHz CD's I'm wondering what Apple has done to deal with the heat problem. Obviously the thermal design was vastly improved. Insight? Ideas?
 
phoenix78 Nov 8, 2006 08:43 AM
One angle is that the C2D is more energy efficient than the CD while improving performance. so straight away that would explain a difference in temps. I think this would be the most significant factor since it is a big culprit in producing heat.

I also imagine that apple has put significant effort in routing the heat more effectively than in the CD models... since many complaints were made about it.

i also assume that the logic boards have been revised to be more efficient.

All this is speculation though but i imagine that it is reasonable to assume that enhancements have been in many areas based on the experience from the CD model.

:)

im glad to hear the C2D are better as far as heat goes. im thinking of getting the C2D macbook... as im typing the apple store webpage is being updated... so heres hoping for a macbook release with much improved heat performance.
 
Simon Nov 8, 2006 08:46 AM
As I said, the TDP of the C2D is no lower than that of the CD and since the C2D is 2.33 GHz and the CD is 2.0 GHz there's no reason to assume the heat output of the C2D is any lower. Obviously it's the heat transport that was changed.
 
phoenix78 Nov 8, 2006 08:59 AM
Yep the TDP is comparable but slightly higher than the CD infact.... 34watts from 31? This is coupled with the increase in performance meaning that it does more work per clock cycle so the cpu gets rid of its load faster and will spend more time idle than the CD for the same amount of workload.... this may reduce theheat produced since it will be drawing less current on average.

but if you are doing something cpu intensive for a log time like video editing im sure they would both get quite warm...

actually thats a good test... test it over a long time under constant load and then check the temps...

:)
 
Simon Nov 8, 2006 09:45 AM
Did that as well. C2D never reached the CD temps under high load.
 
Elektrix Nov 8, 2006 10:00 AM
Check out the vents on the back of your C2D MBP and comparer them to your CD MBP.
 
Simon Nov 8, 2006 10:27 AM
I looked into that as well. At first they look rather different. But then you realize that they're not that much different than before. It's just that the grill is now painted in black so you don't actually see it giving the impression there are large holes in the back. In reality the grill seems very similar to what I have on my CD MBP.
 
Elektrix Nov 8, 2006 11:04 AM
Simon, it is more than that. The actual slots on the rear are now two rows of 6 wide slots (the top row is easier to see if you look down through the top with the case open), rather than a ton of individual slots. That is making a difference, and allowing for better airflow out the back.

I'm talking more about the slots themselves. It's not just that something is painted in black.
 
bigmike Nov 8, 2006 11:27 AM
Quote, Originally Posted by Simon (Post 3197456)
As soon as I received my 2.33 GHz C2D MBP I noticed that its case feels a lot cooler than my original rev A 2.0 GHz CD MBP. The warmest area is still on the underside but whereas on the CD MBP the upper side of the case always felt pretty warm (and the part between F keys and screen got really hot), the upper side of my C2D MBP is about room temperature.

So I took an infrared thermometer just to make sure I wasn't kidding myself. Both were on the same table and both were running the same stuff. Indeed the palm rest areas of the new MBP are on average about 15C/27F cooler.

I also ran smcFanControl and noticed that the C2D's minimum fan speed is set by Apple to 2000 rpm (fortunately it's still dead quiet :thumbsup: ) whereas the CD MBP's fans have a minimum of 1000 rpm. But is that enough to make a difference? No. When I set the CD's fans to 2000 rpm minimum speed the surface temp didn't change significantly, even after hours of use.

My CD MBP (an early model) is getting a new logic board soon anyway and I'm anxious to see if that changes anything, but even if it does I doubt it will be as much as 15C/27F. And since the TDP of the new 2.33 GHz C2D is certainly not lower than the 2.0 GHz CD's I'm wondering what Apple has done to deal with the heat problem. Obviously the thermal design was vastly improved. Insight? Ideas?
You only said on average 15 degrees lower... exactly how hot does your CD MBP run?
 
Simon Nov 8, 2006 11:37 AM
Surface temp when idle: 45C/113F
 
Burn Nov 8, 2006 07:59 PM
Quote, Originally Posted by Simon (Post 3197917)
Surface temp when idle: 45C/113F
Surface temp, as in you're using an external temp monitor? That doesn't impress me much.. I've been using my 2.16CD on my lap for the past hour.. email, web, cpl other light things.. my processor temp is hovering at 43 to 45c.
 
bishopazrael Nov 8, 2006 08:11 PM
Well whatever the reason... it's good news if its a trend, and it doesnt turn out that his machine is actually a fluke.

I thank god every day for smcfancontrol. that thing works WONDERS!
 
Burn Nov 8, 2006 10:24 PM
A trend of what? Maybe I am in the minority, I know there HAVE BEEN a lot of problems for some people. But since some update a month or two ago, this has been the norm for me.

Don't get me wrong.. it IS a good thing that these 'books can run a little cooler... but it just isn't news is what I'm sayin :) When people were speculating that the new machines would run cooler... I always wondered how cool they wanted it... it doesn't appear to be a vast improvement from the more recent 2.16 MBP's.
 
Simon Nov 9, 2006 03:43 AM
Quote, Originally Posted by Burn (Post 3198681)
Surface temp, as in you're using an external temp monitor?
Exactly. I could care less about the CPU temp as long as it's below its operating max. What I care about is how the thing feels when I type on it. And there I've noticed a very considerable difference.

Quote
That doesn't impress me much.. I've been using my 2.16CD on my lap for the past hour.. email, web, cpl other light things.. my processor temp is hovering at 43 to 45c.
I measured 45C on the palm rest of my CD MBP! And now I measure as low as room temperature at the same location with my C2D MBP (that is however running a 16% higher CPU clock and a significantly higher clocked GPU too).

Impressed or not, that is a great improvement. And it clearly makes the thing more comfortable to use. Apple does listen. :thumbsup:

That said, I'd still like to hear if anyone can offer details on how they changed the thermal design to improve heat dissipation to ambient air.
 
bigmike Nov 10, 2006 01:18 AM
It depends a lot on room termperature as well ... When I turned on the air-con and room temp is about 22 degrees, the palm rest is not warm at all ... but when I am using it outdoor, at 26 degrees, the difference could be noticeable.
 
quattrokid73 Nov 10, 2006 01:23 AM
i didnt know the MBP has a temp sensor...

how do i find my temp?

thanks adam

PS, its a Core Duo
 
Simon Nov 10, 2006 03:58 AM
Quote, Originally Posted by bigmike (Post 3200168)
It depends a lot on room termperature as well ... When I turned on the air-con and room temp is about 22 degrees, the palm rest is not warm at all ... but when I am using it outdoor, at 26 degrees, the difference could be noticeable.
I agree that room temp is important. I noticed the difference well between using it in a room with AC and using it outside in the sun.

That's why I did my temp measurements with both MBPs sitting right next to each other.
 
Simon Nov 10, 2006 04:01 AM
Quote, Originally Posted by quattrokid73 (Post 3200174)
i didnt know the MBP has a temp sensor...

how do i find my temp?
You can for example use a simple tool like smcFanControl to show you the temp. There are many others.

The external case temperatures I mentioned were acquired using an off the shelf infrared sensor we had lying around in the lab.
 
MrN79 Nov 12, 2006 06:34 AM
Quote, Originally Posted by quattrokid73 (Post 3200174)
i didnt know the MBP has a temp sensor...

how do i find my temp?

thanks adam

PS, its a Core Duo
Not sure if you like using Dashboard Widgets, but here is a link that will show you what temperatures are monitored in your MBP C2D. It says there are 9 different temp sensors that you can choose up to 2 to monitor.

http://www.apple.com/downloads/dashb...etedition.html
 
Simon Nov 22, 2006 03:24 AM
I just got my rev A MBP back from warranty repair for a dead right fan and a motherboard problem reported by AHT.

The rev A MBP is now actually running cooler than before, but it is still roughly 10C higher than the rev B C2D MBP when idling. I guess the updated rev A motherboard design (the new motherboard requires 10.4.6 whereas the original motherboard ran 10.4.5 so I got new install DVDs as well) has been improved in terms of heat and the CPU whine is gone too, but the case is still definitely warmer than on the C2D MBP.
 
bernt Nov 22, 2006 03:47 AM
The guys over at Hardmac.com : Le "Macbidouille" in English have discovered that the fans are different in the rev B MBP. That could also be part of the reason for why the rev B's are cooler. The new fans should be more effective and less noisy.
 
Simon Nov 22, 2006 04:47 AM
Well they certainly sound different at equal RPMs so I'm not surprised to hear they're actually different models. It could well be that the new fan design is more efficient.
 
Gee4orce Nov 22, 2006 05:59 AM
Maybe they applied the thermal paste properly this time ? ;)
 
11011001 Nov 22, 2006 08:58 AM
Oddly enough, my C2D is running cooler than my G4. That's a nice surprise.
 
bloodline Nov 26, 2006 07:35 AM
The C2D is very cool running! reasons:

1) A better heat pipe.
2) Cooler running CPU.
3) Faster minimun speed on the fans.
4) More responsive fans, they react to temp changes more quickly
5) The radiator is now exposed at the back of the machine, rather than being covered by a plastic grill as in the CD MBP.
 
Kamikaze Nov 26, 2006 09:56 AM
Anyone think that it is worth me upgrading to the new heatpipe on my CD?
I thought I'd use Artic Silver and the new pipe.

Thx
 
pokeman Nov 26, 2006 10:58 AM
Quote, Originally Posted by Simon (Post 3199026)
I could care less about the CPU temp...
Sorry for whining, but that implies that you do care, and that there is scope to care less. I see this American phrase all the time. Shouldn't it be "I couldn't care less"?
 
firefly Jan 2, 2007 11:54 AM
Quote, Originally Posted by pokeman (Post 3219330)
Sorry for whining, but that implies that you do care, and that there is scope to care less. I see this American phrase all the time. Shouldn't it be "I couldn't care less"?
Questions & Answers: I could care less
 
dpicardi Jan 2, 2007 08:16 PM
Quote, Originally Posted by firefly (Post 3255719)
My personal fav is irregardless. ;)
 
siflippant Jan 3, 2007 03:56 AM
Quote, Originally Posted by dpicardi (Post 3256183)
My personal fav is irregardless. ;)
:thumbsup:
 
kamina Jan 3, 2007 03:36 PM
My macbook pro has allways been ridiculously hot, so much that you can't touch the left speaker or area above the function keys for a long time if it's under load. My new teammate got a C2D mbp about a month ago, and sure enough it was alot cooler!

I was annoyed, but did'nt think too much about it. One day I downloaded coreduotemp (shows the processors temperature) and started it up. When I was stressing my cpu the temperature was up to 96C, pretty high considering Intel has stated the absolute maximum temperature for a CD processor is 100C (allready the highest max temp I ever saw for any processor). This temperature was measured in 21C ambient temperature with the notebook on a wooden table.

Needless to say I got worried, and decided I have to send the notebook to be repared. However the Apple reprasentative I reached from their support stated that "Processor temperatures of 100C are completly normal for a mbp"... Ok, I guess Intel's guidelines don't mean much, good thing I have applecare!

I took an identical laptop which just has a faster processor, and did a profile transfer to it. I thought I'd test how hot this can really get under normal operation. I put load on the processor, started a large file transfer and the temps went to 96C. I then started to play Sourbraten (a 3d "game" which will stress the videocard), and the whole screen got garbled. No way to see the temp, so I did'nt manage to get above the "perfectly normal operation temperature". However Apple now accepted to take the notebook for repairs due to a "faulty videocard" :brick:

Sorry, I started rambling... Now back to the point.

When I had done the profile transfer to the new mbp, I did the exact same test on it. It ran at 64C, which was 32C lower. This is with both machines next to each other on the table. According to apple it is normal that there is such a difference in temperature even though everything is equal (temperature measured on both notebooks with 10 minutes of 100% cpu load using the same application to generate it [folding@home]).

Both notebooks are rev1 mbp's, the hotter one has a 1.86ghz processor, cooler one has a 2.16ghz processor. Both have 2GB ram.

So... It's actually normal that there is 32C temperature difference between mbp's of the same revision, making my guess that one of the main changes is how they transfere the heat from the processor to the heatsink (first models having problems with heatsink contact or some other design fault).
 
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