Chosen Solution
My mac pro has been running very hot and lately, it totally shut down by itself. I can see that it is running very hot and the fans had been on top speed all the time. I am wondering whether if i change the thermal paste to the CPU would help to reduce its heat and improve its performance. Attached is a screenshot of my mac pro temperature.
Update: I have managed to opened up and fan and gosh, the amount of dirt accumulated is ridiculous. Managed to cleaned up all the dirt and now my fan is barely activating. i shall monitor it for a while to see whether it starts to heat up again before i change the fan.
Hello Kelvin Wong! Before you try anything drastic, I would recommend that you just give your Mac Pro a good dusting. This is usually the problem in these types of machines and will usually drop your temperatures about ten degrees. While you are in your Mac Pro, I would also recommend replacing the thermal paste on at least on the CPU. The GPU could also be done as well if it is running hot. Chances are that the thermal paste in your machine is dried up. After sealing the Mac Pro back up and powering it on, I would recommend installing a free application called Macs Fan Control. It is one of the best fan control utilities for Macs and it works really well. You can find the download link for Macs Fan Control here: https://crystalidea.com/macs-fan-control… Check the CPU die or core temperatures as well as the temperature of other temperature probes inside of your Mac Pro. These are listed in the right panel of the application.
It is considered normal for a Mac to idle at 40-50 degrees Celsius depending on what type you have. I would say 50 degrees is too hot for a desktop Mac to idle at, so you can change the fan settings to make it idle cooler. You will need to do a little bit of experimentation with this, as I have never owned a “trashcan” style Mac in my life. What I can tell you is that the CPU core or die temperatures should never go over 80 degrees Celsius under load, especially in a desktop. I would recommend changing the fan curve for the exhaust fan in your Mac Pro. To do this, click on the custom control button for your Mac Pro’s exhaust fan. Set the control option to sensor-based value. Change the temperature sensor to either the CPU die or the CPU core average. I would recommend setting the temperature to start ramping up the fan to about 50-60 degrees Celsius depending on if you want your Mac Pro to idle cooler or quieter. Set the maximum temperature to about 80-90 degrees Celsius respectively. Let me know if this resolves your issue. I would recommend trying this first before going and replacing the fan or heatsink. Chances are that if the fan is spinning at full speed most of the time, something is blocking its airflow or the heatsink’s heat transfer ability. Have a great rest of your week!
So far your thermals look within reason. But clearly the fan is running hard! Its time to run the onboard diagnostics to be sure SMC is not seeing any errors. Restart your system and press the D key to enter. Did you get any errors? Ley us know. Reference: Mac startup key combinations If you don’t get any errors then your issue is strictly within the fan and you’ll need to get a new one Mac Pro Fan, Apple P/N 923-0491
Normally it’s something I recommend as a quick TSing step to rule TIM out, but on these trashcans it’s not for the faint of heart and you need to know how to do it right, or you’ll create expen$ive damage :-(. The issue is Apple removed the metal bracket Intel installs to gain a little space back due to the needs of the trashcan cooling system. In most systems like this it isn’t an issue if you trash a CPU as they’re often cheap enough to replace (or it was done sensibly, as in the CPU socket is on the bottom and the CPU comes off with the heatsink, so it’s low risk), but Xeons are NOT CHEAP - you do not want to ruin one, or the socket! They’re amazing CPUs when you can score cheap Xeon hardware (I would say yes to the Xeon version of the same machine, without a question), but you do not want to damage the CPU or socket since the damage is far more expensive to correct then a standard Core i CPU. Yes, it can and often does help, but please look into the option @danj mentioned first - you’re not going to put the system in as much risk that way.
