Cooling solutions for the Mac minis?

[bzgnyc2]

I struggle mightily with my 2018 mini. If my upstairs gets into the 80s, it just shuts down. I run security spy on it, have it on its side with air all around it.

Can you share some numbers from Macs Fan Control when it's idle?

Also can you share some screen snapshots from Activity Monitor (CPU tab, sorted by decreasing % CPU) when you think it's idle?

I've never had a thermal shutdown on my Mac Mini 2018 and that includes running it flat out for a week+ at a time with all CPUs going and a recent period where it was >85 deg F in my home due to an AC issue.

Thinking of upgrading to a M1 or 2 but this mini has 32gb of memory and 1 tb drive in it.

M1+ will of course be faster and run cooler. Unfortunately as you know matching RAM capacity gets expensive at the high-end with Apple Silicon. Getting close with a new M4 w/24GB and 1TB will run $1200. An M4 Pro w/48GB and 1TB will hit $2K (at which point, buy a Studio) with shipping dates in September. Worse, Ebay prices for M1 and M2 w/32GB even higher than Apple's price for new M4...

If your current system otherwise meets your needs, I would try to fix it. What you are experiencing is not normal. Mine is currently running 50 deg C while streaming video with a several background apps running. Thermal throttling not to mention thermal shutdown doesn't really start until 100 deg C. Add 10 deg to my number to account for cooler ambient temperature (though I am probably only 5 deg C less than you) and you aren't even close.

 

[skodises]

I struggle mightily with my 2018 mini. If my upstairs gets into the 80s, it just shuts down. I run security spy on it, have it on its side with air all around it. Thinking of upgrading to a M1 or 2 but this mini has 32gb of memory and 1 tb drive in it.

I agree with sauria: replacing the OEM thermal paste really can be extremely helpful, in my experience. And the removal of the fan and heatsink during that process provides a great opportunity to do a thorough cleaning, since both of those are serious lint traps. Also count me as a very satisfied user of Macs Fan Contol.

My solution, described above, was to use an external 140mm fan to literally force-feed the machine with additional cooling air, with the bottom cover and antenna plate removed. I now actually have the machine gasketed to the fan base, so that 100% of the external fan’s output creates turbulent flow throughout the case and is then forced to exit through the blower via the heatsink’s exhaust port. This has the somewhat gratifying effect of keeping the outer case cool to the touch, and the processor and memory temps are as shown above. Consider installing the Intel Power Gadget to get a feel for how things are, and see the improvement you get from each step you take. It has been discontinued, but can still be found here: https://intel-power-gadget.macupdate.com

But the first step should definitely be the thorough cleaning, and paste replacement with modern paste. By design, essentially all of the processor’s waste heat must be rejected to the air via that heatsink: so any increase in thermal resistance at the die/heatsink interface will inevitably result in higher die temps, and excessive throttling on even nominal loads. At ~80degF ambient, you will need all the help that fresh, non-dried-out paste can give you, IMNSHO.

One superannuated nerd’s opinion- your mileage may vary. Hope that helps, anyway…

 

[Richard8655]

Anyone have idea if placing the mini on some kind of raised grate that allows air to freely circulate or mounting it vertically so that more surface is exposed to freely circulating air would have any benefit?

Yes, that's very helpful in my opinion. All my Mini's I've owned, I attach 4 small plastic feet (adhesive on each side) to the bottom. That raises the Mini about a quarter inch above the desk surface. Air can flow and dissipate from the bottom rather than acting as a heat collection location. Simple but effective IMO.

 

[harriska2]

I agree with sauria: replacing the OEM thermal paste really can be extremely helpful, in my experience. And the removal of the fan and heatsink during that process provides a great opportunity to do a thorough cleaning, since both of those are serious lint traps. Also count me as a very satisfied user of Macs Fan Contol.

My solution, described above, was to use an external 140mm fan to literally force-feed the machine with additional cooling air, with the bottom cover and antenna plate removed. I now actually have the machine gasketed to the fan base, so that 100% of the external fan’s output creates turbulent flow throughout the case and is then forced to exit through the blower via the heatsink’s exhaust port. This has the somewhat gratifying effect of keeping the outer case cool to the touch, and the processor and memory temps are as shown above. Consider installing the Intel Power Gadget to get a feel for how things are, and see the improvement you get from each step you take. It has been discontinued, but can still be found here: https://intel-power-gadget.macupdate.com

But the first step should definitely be the thorough cleaning, and paste replacement with modern paste. By design, essentially all of the processor’s waste heat must be rejected to the air via that heatsink: so any increase in thermal resistance at the die/heatsink interface will inevitably result in higher die temps, and excessive throttling on even nominal loads. At ~80degF ambient, you will need all the help that fresh, non-dried-out paste can give you, IMNSHO.

One superannuated nerd’s opinion- your mileage may vary. Hope that helps, anyway…

We did replace the thermal paste and cleaned the fans. Still overheats. I’ll look into the fan control. It was pretty much running the whole time. Might just do the paste and cleaning again, it’s been a couple years.

 

[bzgnyc2]

We did replace the thermal paste and cleaned the fans. Still overheats. I’ll look into the fan control. It was pretty much running the whole time. Might just do the paste and cleaning again, it’s been a couple years.

One of your previous posts mentioned an idle temperature of 50-55C. Which component was this measuring? I usually base on CPU PECI. Also your signature didn't mention which model of Mac Mini 2018 -- do you have an i3, i5, or i7? They are all rated the same TDP but pretty sure the i3 idle and peak TDP are less than the i7's (and therefore Mac Mini systems with the latter will run hotter given the cooling system is otherwise the same).

However, your 50-55C idle temperature isn't that high and should be far away from thermal shutdown (which I am guessing is at least 105 deg C or higher -- not sure as my Mini throttles itself before any component gets much over 100 deg C). I would monitor the temperature with Macs Fan Control to see which component is reaching which temperature to initiate a thermal shutdown (i.e. which component what highest temperature right before it turns itself off).

Not saying not to do the paste and cleaning at some point. Just get the baseline readings first so you know you've isolated the issue(s) and whatever changes you make are intentional.