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First generation MBP temperatures

J

jeckyll88

macrumors newbie
Original poster
Mar 24, 2011
11
0
I have a first generation Macbook Pro (core duo 2.16ghz) and I have been keeping track of the temperature sensors lately to get an idea of how hot it runs under different loads. I plan on keeping this thing for as long as possible so I want to know when something starts to go wrong. I have been using a program called temperature monitor as well as istat pro.
Everything seems to be running at normal temperatures for this old model under idle conditions. The weird thing is that under high CPU loads (encoding videos mostly) the sensor labeled "CPU A Temperature Diode" is much higher than "CPU Core 1", "CPU Core 2" and "CPU A Proximity". For example, with an HD netflix video playing the cores and proximity are all 64C +/-1C and the temperature diode is 79C. Under nearly 100% CPU, the cores and proximity get up to the high 70s and the temperature diode can surpass 110C. When the load stops the diode falls very rapidly to its idle value.
Here is a graph for an test of 100% CPU. The diode temperature is obviously the high one and the other CPU ones are the ones below (not the straight horizontal ones, i dont know what those are).
It doesn't make any sense for the difference between the cores and the diode to be so great considering there locations are so close on the chip. Clearly, the temperature reading is wrong and it is somehow being scaled. I have searched around and have found nothing. I have noticed on another computer that the cores and the diode are usually the same temperature (+/- 2C) under all conditions. I have no concerns about any actual overheating but I am concerned that the computer will shut down automatically if it is sensing such a high temperature. Does anyone have any idea whats going on and how to possibly fix this?
 
Your temps are quite normal for the load you're putting on the system. Macs are designed to automatically shut down to avoid damage if temps are sustained at a high temp (around 105C) for a period of time, not just a spike. Unless your Mac is shutting down due to temps under normal use, you're better off forgetting about temps and just using your Mac.

If you want more information, here are just a few of many threads on this topic, found by searching the forum with Google:

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I dont see how 110C+ is normal. Using handbrake to encode a movie today I got temperatures of up to 123C before I stopped the encode. Strangely, I did the same encode in handbrake in windows 7 (also installed on this computer) and the temperature never surpassed 98C. In both cases the processor was going at 100% in both cores. I dont see how this discrepancy is possible considering they are readings from the same temperature sensor.
 
jeckyll88 said:
I dont see how 110C+ is normal. Using handbrake to encode a movie today I got temperatures of up to 123C before I stopped the encode. Strangely, I did the same encode in handbrake in windows 7 (also installed on this computer) and the temperature never surpassed 98C. In both cases the processor was going at 100% in both cores. I dont see how this discrepancy is possible considering they are readings from the same temperature sensor.
Click to expand...
Apparently, the threshold for the Core Duo is higher than for the Core 2 Duo and subsequent processors:
If Intel Thermal Monitor automatic mode is disabled, the processor will be operating out of specification. Regardless of enabling the automatic or on-demand modes, in the event of a catastrophic cooling failure, the processor will automatically shut down when the silicon has reached a temperature of approximately 125°C. At this point the THERMTRIP# signal will go active.
Click to expand...
 
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So right now my CPU is 100%, the temperature reads 115C and the fans are ~4400 RPM. I know the fans can get up to 6000 RPM and im pretty sure if temperatures are really getting to 110C that the fans should go at full speed. I've dumped Temperature Monitor and and only using iStat pro. I know I can use SMC fan control to manually raise the fan speeds but this should really happen automatically at high temperatures. Something funky seems to be happening and I dont know what. I have tried that thing where i turn the computer off and take the battery out and hold the power button in for 5 seconds, but that seems to do nothing. Does anybody out there have this model and are experiencing something similar?
 
jeckyll88 said:
So right now my CPU is 100%, the temperature reads 115C and the fans are ~4400 RPM. I know the fans can get up to 6000 RPM and im pretty sure if temperatures are really getting to 110C that the fans should go at full speed. I've dumped Temperature Monitor and and only using iStat pro. I know I can use SMC fan control to manually raise the fan speeds but this should really happen automatically at high temperatures. Something funky seems to be happening and I dont know what.
Click to expand...
Are you concerned that, at those temps, the fans are spinning at 4.4K, rather than spinning up to 6K to pull the temps even lower? If it's working as designed, the fans will spin only fast enough to maintain temps at a safe level, but not necessarily to bring them down as far as they might at full speed. Apple doesn't document exactly what that "safe level" might be.
 
GGJstudios said:
Are you concerned that, at those temps, the fans are spinning at 4.4K, rather than spinning up to 6K to pull the temps even lower? If it's working as designed, the fans will spin only fast enough to maintain temps at a safe level, but not necessarily to bring them down as far as they might at full speed. Apple doesn't document exactly what that "safe level" might be.
Click to expand...

All MacBook Pros get hot when going full blast (I clocked mine at 102c the other day ripping DVDs and encoding) but that's hotter than I remember the early MBPs getting. You might want to get a fan-mat or something to keep it cool. It'll also improve your Mac's life.

Alternatively, you can modify your fan speed, but of course it will drop the battery life: http://www.macupdate.com/app/mac/23137/fan-control for a quick tool.
 
GGJstudios said:
Are you concerned that, at those temps, the fans are spinning at 4.4K, rather than spinning up to 6K to pull the temps even lower? If it's working as designed, the fans will spin only fast enough to maintain temps at a safe level, but not necessarily to bring them down as far as they might at full speed. Apple doesn't document exactly what that "safe level" might be.
Click to expand...

I am concerned that the fans aren't at maximum when the temperatures are so high. Look. Even with smcFanControl at maximum the temperature does still creep up to 125C at which point I pause the encode. Should I just let it rise and let the computer do what its suposed to so I can see what happens?
 
tbobmccoy said:
All MacBook Pros get hot when going full blast (I clocked mine at 102c the other day ripping DVDs and encoding) but that's hotter than I remember the early MBPs getting. You might want to get a fan-mat or something to keep it cool. It'll also improve your Mac's life.

Alternatively, you can modify your fan speed, but of course it will drop the battery life: http://www.macupdate.com/app/mac/23137/fan-control for a quick tool.
Click to expand...

I actually do have a stand with 3 fans. That helps a little but I can still see readings of 120C+ if I have the CPU at 100%. But not in windows for some reason.
 
jeckyll88 said:
Should I just let it rise and let the computer do what its suposed to so I can see what happens?
Click to expand...
That's what I would do. If it climbs past the threshold, it should automatically shut down. If it does, you'll know it's working as designed and you'll know it's safe to let it do what it does.
 
jeckyll88 said:
I actually do have a stand with 3 fans. That helps a little but I can still see readings of 120C+ if I have the CPU at 100%. But not in windows for some reason.
Click to expand...

That's odd, but yeah, if you've got the stand.. personally I'd use the app to modify the speed of your fans. Maybe keep it in your menu bar or desktop to use when you're going into CPU intense apps/environments. But, I'm always paranoid about CPU heat and battery life :cool:
 
tbobmccoy said:
That's odd, but yeah, if you've got the stand.. personally I'd use the app to modify the speed of your fans. Maybe keep it in your menu bar or desktop to use when you're going into CPU intense apps/environments. But, I'm always paranoid about CPU heat and battery life :cool:
Click to expand...

Currently, CPU 100%, fans set to 6000rpm and the temperature is 117C and rising. What I have been doing is pausing the encode if the temperature gets to 120C and then I start it up again when its lower and repeat until the file is done. I kinda sucks but as soon as this file is done i'll let it run and see if it automatically shuts down. Battery life is not an issue, I never really take it off of the AC adapter. I make sure I cycle the battery every few weeks.
Does anyone think it is odd that the cpu temperature diode reading is 40C higher than the core readings? Shouldn't they all be within a few degrees of each other?
 
OK, so I let the thing run and sure enough it shut down automatically. Kinda scary because its the first time this has happened. All I was doing was encoding a movie, which I have done before with no problems (but I wasn't paying attention to the temperature before). Suddenly, I start paying attention to the temperatures and I am geting overheating problems. Since I am only having this problem in OSX maybe I should uninstall everything that records temperature because that might be the problem. I might even do a reinstall of OSX. One thing I will never do is switch to windows to use handbrake :D .
 
I guess its possible. When temperature sensors fry do they usually give weird readings or do they just stop working?
 
Something interesting just happened. I decided to take the battery out and run the computer just off of AC to see if anything would be different. As soon as I hit the power button the fans went 100% and stayed that way. Once I was booted iStat was not showing any temperature sensors except for the hard drive. I rebooted and the same thing happened. I turned it off and put the battery back in and everything went back to normal.
Is it possible that my battery is somehow causing all of this trouble? It has had a "service battery" warning in the battery drop down since I installed 10.6.
 
Could be both and it would interfere with fans working properly.

I would try to get the battery replaced and do a PRAM and SMC reset.
 
adnoh said:
Temps are fine
Click to expand...

IDK... it shut down twice today when it exceeded 125C when encoding a movie.

EDIT: I took the battery out again and this time the fans didn't go all crazy and all of the temperature readings are back. I know the processor doesn't run at full speed when there is no battery but the cpu temperature seems to be much better. I guess ill have to fork out $140 on a new battery to see what happens.
 
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Something that I have been thinking about doing for a while was taking the whole computer apart to clean out all of the dust that accumulated over 5 years and to reapply the thermal paste. I have replaced the hard drive before so I am not new to opening up this model. I took my time and everything went well but I was absolutely shocked to see how much thermal paste apple used.
31079873.png

I cleaned it all off and put on the correct amount of arctic silver 5. It runs a little better now but it can still creep up to unusually high temperatures and shut down at high loads.
I think I did everything right based on other posts, but I just wanted to make sure. This model has the logic board resting on the heatsink (heatpipe?) and there does not seem to be any pressure besides that caused by securing the logic board to the bottom case with screws. I used the standard method of applying a thin, even layer of paste to processor (and the other two chips in this case). Is there a better way to do this on the MacBook Pro 1,1 or was this the correct method?
 
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