Mac mini 2018 - Thermal management / Cooling solutions
Here are some suggestions from iMore. I have not tried them myself but it seems easier than DIY solutions.
I thought I would jump in here as I have done extensive testing (as an amateur, I'm not Gamers Nexus). I tested the system as is, the system running MacFansControl with a more aggressive curve, with Fans All on, with the SPEED cooling solution (stock), SPEED cooling solution (modified).
Anecdotally, the best performance came from running the internal fans at max all the time with the existing plastic intake as is. For the SPEED solution, upon simplistic testing, I found that the existing Mini antenna plate and Mini internal fan pairing restrict the flow to a limit based on that... (I did not measure airflow rates). Therefore, I hypothesized that additional forced air did nothing but cool the antenna plate but not enough useful ambient air is being pushed to the internals... if anything, it is creating turbulence, restricting the flow as designed by Apple (look at the ifixit, you can see how the air can collide with the internal fan hardware).
I did see a user post a radiator bolted on to their mac mini case. I replicated this using ARCTIC thermal pads and a correctly sized Heatsink. This showed slight gains in an ambient 22C room but not enough that it would fall outside of my comfortable +/- on error.
My next experiment would be to introduce either induction cooling through an additional iron plate somewhere (which I am worried about for other reasons) or by attempting to water-cool (aka like a CPU cooler) the exterior chassis.
The final test would begin to diminish the Mac Mini and more about just being curious... by removing the antenna plate (so, no more wifi) and removing the internal fan. The question this would answer: does the SPEED solution (at 2200 RPM but a much larger fan) provide better flow than the internal fan at full RPM (I don't remember the specific # off hand).
FYI, Macs Fan Control is now working on Windows Boot Camp even on models that are equipped with the modern T2 Chip! You can now manually control the fan speeds! I tried testing it on my Mac Mini and play The Witcher 3 on high settings and the temps were around 65 to 75. By the way, I set my fan to just 3400 RPM. I didn't test it to max (4400 RPM). I guess the temps will become lower if I set it to max.
Macs Fan Control: https://www.crystalidea.com/macs-fan-control
@naurisolento, I'm just showing up on the scene having just pulled the trigger purchasing the 2020 Mac Mini which is supposed to have better air cooling, but YouTubers are still reporting the machine is hot and it still gets throttled under load). Doing my research, I did see someone say in a review "the Mac Mini (new 2018) is running around 20 degrees cooler than when it was flat." on the last product listed on that iMore Guide, the Tinpec Mac Mini Aluminum Stand. Seems a bit dubious to me but that's what they said, my guess is they're just spitting out an impressive sounding number?
The top review on that same product "…Not only does this minimize the footprint on a desktop, but I'm pretty sure it improves the air flow in the box. The CPU is at the back corner nearest the SDXC slot. By placing the Mini so that this corner is at the top, not the bottom, then hot air flow more naturally flows out of the box, which should help keep the inside of the enclosure cooler. The best possible position is with the front face of the Mini facing DOWN, and the cables facing UP. However, this looks pretty ugly with all of the cables visible for everyone to see. Second best position is with the face of the Mini facing forward and the cables at the back, and the Mini's bottom at the left (SDXC slot pointing up)."
Joined to let you all know this forum helped me increase the performance of my 2018 mac mini (3.2ghz i7) by about 10% and lower the idle temp about 5c...
- Thermal paste Arctic MX-4 ( https://www.amazon.com/gp/product/B0795DP124/)
- 2 Fat heat sinks sit on top painted space grey ( https://www.amazon.com/gp/product/B00VG6WPKK/)
- Top heatsink thermal pad ( https://www.amazon.com/gp/product/B075JCQPD2/)
- Top heatsink thermal tape ( https://www.amazon.com/gp/product/B075FR45DV/)
- 32GB ram updgrade while i'm in there ( https://www.amazon.com/gp/product/B071H38422/)
- Macs Fan Control set to 3000rpm
Before the mods with nothing running at idle with mac fan control at 3000 rpm it was reading 41.0c on average. After the mods it sits around 35.5c on average.
Ran geekbench before the mods and with just the top heatsink and then all in, you can see the top heatsink doesn't add a big benefit but it looks cool but the thermal paste really helps and this was my first time doing thermal paste so probably a bit sloppy. Here are the geekbench results showing about a 10% performance gain...