Mac mini 2018 - thermal solutions thread  

Page 1 / 2 Next
  RSS

expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 6:32 pm  

On the recommendation of @itsage, I have started this separate thread for us to discuss potential thermal solutions for the 2018 Mac mini. Here is a summary of where we are and what we know so far:

  • Manual control of fan not currently possible - @johnjkle has reported SpeedFan as not being able to detect a single fan.
  • Undervolting is not a solution on this CPU.
  • Exhaust fan to suck air out is unlikely to be viable - @danhc has pointed out that this could damage the internal fan by increasing its RPM.
  • Blowing fan to push air out has been developed for previous mac mini - there are no reports, however, of how effective this is or what damage it could cause to the internal fan. Other potential solutions, such as a laptop cooling pad, are also unknown quantities in both effectiveness and potential damage. 
  • Standing the mini on its side without lid has not been tested but the consensus so far is that this is unlikely to help anything.

 

Some have also reported that the fan is not very loud when the CPU heats up. This would imply that its not running to its full capacity or is simply not a very good fan. There may be therefore some potential solution down the line in terms of an Apple firmware update or a DIY fix through a third party application.

Others, such as @anethema, have pointed out the possibility of a 3D print solution: "considering the circle on the bottom is only a press fit, a neat part to model would be a 3D printed circle that press  fit in and has a mount for like a 120mm fan". This is similar in concept to the blowing fan developed for the previous mac mini.  

I will be purchasing my mac mini at Christmas but, until then, I will be brainstorming for solutions to this issue. In the meantime, I'm hoping we can all put our heads together and see what we can come up with! I will be updating this post as we go along.  


bluetech and theitsage liked
ReplyQuote
mac_editor
(@mac_editor)
Noble Member Moderator
Joined: 2 years  ago
Posts: 1474
November 9, 2018 7:03 pm  

@expensivefruit What about thermal repasting/liquid metal?

purge-wrangler.shpurge-nvda.shset-eGPU.sh
----
Troubleshooting eGPUs on macOS
Command Line Swiss Knife
----
Multiple Build Guides


Joikansai liked
ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 7:09 pm  

@mac_editor I haven't seen anyone report anything yet but I've heard/read before that the thermal paste Apple use is pretty poor. I did see someone on macrumors post a photo where they applied more thermal paste after they added RAM, although this was before they even ran the god damn thing, so it's hard to say what their performance gain has been. I'll see if I can track down that post and ask the poster to run a test. What sort of gains do you think can be made using more and/or good paste? I have no experience in applying it so I'm not sure what the process is like - hopefully others can contribute on this.


ReplyQuote
mac_editor
(@mac_editor)
Noble Member Moderator
Joined: 2 years  ago
Posts: 1474
November 9, 2018 7:14 pm  

@expensivefruit I have re-applied thermal paste only once, on my older 2014 15" MBP and the results were generally positive. Without changing any fan curves I noticed that the fans seldom ramped up in macOS post re-application on medium load. While the system still throttled at max. load (a given on something like an MBP), it occurred less often and less severely. I do not have numbers to back up my experience however. In my opinion a combination solution of good thermal paste and a better fan curve (if any app comes up that supports the same) would be a great starting point on the Mac mini.

purge-wrangler.shpurge-nvda.shset-eGPU.sh
----
Troubleshooting eGPUs on macOS
Command Line Swiss Knife
----
Multiple Build Guides


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 7:45 pm  

People on this forum seem to be suggesting that the mac mini already has a lot of thermal paste and any more could have the opposite effect.


ReplyQuote
theitsage
(@itsage)
Famed Member Admin
Joined: 2 years  ago
Posts: 3075
November 9, 2018 8:11 pm  

@expensivefruit The majority of Macs left the factory with more thermal paste than needed. I cleaned the CPU die and heatsink in my Mac mini when I had it apart. I then applied a thin coat of Thermal Grizzly Kryonaut using the included plastic spreader tool. My guess is the firmware is tuned for low noise rather than aggressive fan curve.

Best ultrabooks for eGPU use

eGPU enclosure buying guide

82 external GPU build guides


ReplyQuote
mac_editor
(@mac_editor)
Noble Member Moderator
Joined: 2 years  ago
Posts: 1474
November 9, 2018 8:19 pm  

@expensivefruit Having more thermal paste is not the same as better performance. More can be bad as @itsage points out. Also the quality of thermal paste matters too. Apple has historically used poor compound. I did not suggest adding more thermal paste - rather replacing it with better compound (so one cleans off the previous paste completely and then re-applies the new one).

purge-wrangler.shpurge-nvda.shset-eGPU.sh
----
Troubleshooting eGPUs on macOS
Command Line Swiss Knife
----
Multiple Build Guides


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 8:27 pm  

@mac_editor & @itsage thank you both for clarifying. Is removing and reapplying an easy/straightforward process? Also, @itsage, do you think in your case it has helped at all? I expressed these thermal issue concerns on macrumors and someone who has already purchased their mac mini seems to be pretty insistent that the high temperatures are not something to worry about. When I pushed him on this he gave me this answer:

"Nobody is doing it consistently. I do video encoding twice a week. That's the only thing I do that stresses it. So not often.
Intel has spec limits on it, they have systems to slow the frequency down to reduce temperatures when they feel it's too hot. When encoding and mine is in the 90's it's still running above base frequency so they're clearly ok with it running at that temp otherwise they would throttle it sooner and more aggressively. I'm really not worried about it.

Maxing a CPU will push it's temp. Not just in a mini but even in your desktop PC's. Even my watercooled PC is still in the upper 80's when encoding. Imagine with just a fan on that! I encoded with previous computers with only a CPU fan and they would also hit the 90's. No issues. The system will shutdown to prevent damage though i've never actually seen it happen as it uses it's other systems to bring the temp down first."

Thoughts? 


ReplyQuote
DanHC
(@danhc)
Eminent Member
Joined: 6 months  ago
Posts: 36
November 9, 2018 8:30 pm  

@expensivefruit

(See 12:45)

In this video Linus did the exhaust fan trick and his laptop CPU got up to 5Ghz.
So Vacuum Fan solution must work. For the damaging the internal fan part, I am skeptical about, say if the fan run higher than its max speed (say 2000rpm) higher due to air being drag out of the cooling assembly, it won't exert much more friction on it to be honest. And even if it happens, I think Apple would still replace it.... all they could see from inspection is a "defective" fan..... haha

So if we vacuum air from mac mini's exhaust vent, I am sure it will work....... In extreme case, say we just connect a 2000W vacuum cleaner to it's exhaust and seal it off....... the wind will be so great that I doubt it will even hit 80C, but then will it be so strong it may suck the capacitors out of the board LOL


ReplyQuote
mac_editor
(@mac_editor)
Noble Member Moderator
Joined: 2 years  ago
Posts: 1474
November 9, 2018 8:36 pm  

@expensivefruit Apple generally prefers low-sound-first fan curves and all their Mac products typically run hot. While it is true that nothing will happen to system even if it is running hot for long periods (example: my older 2014 MacBook Pro - did some encoding that lasted days, and frequently pushed it far and beyond with and without eGPU - never any issues or repairs needed - this is before thermal paste change - lasted 4 years until I just upgraded - it was fine), going the extra mile is certainly not a negative in any way (except perhaps one messing up something and destroying their board) in terms of life-lengthening or performance.

In summary, people aren't applying thermal paste to macs for longevity (they last long regardless), but to eek out any modest performance gains possible with better compound and if possible reduce throttling at high load.

purge-wrangler.shpurge-nvda.shset-eGPU.sh
----
Troubleshooting eGPUs on macOS
Command Line Swiss Knife
----
Multiple Build Guides


theitsage liked
ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 8:39 pm  

@danhc interesting find. In that case, may it be worth investigating some kind of DIY solution using a normal fan externally connected to some kind of makeshift power supply? I'm not an electrician or that good at DIY (adding the RAM in the mini will be my limit), so unless there's a plug and play solution ready on the market, how would one go about this?


ReplyQuote
DanHC
(@danhc)
Eminent Member
Joined: 6 months  ago
Posts: 36
November 9, 2018 8:50 pm  

@expensivefruit

I think adding ram is much easier than this..

The difficult part to exhaust fan trick is when we want elegant to it.... I mean if you get these then seal it off with the Mac Mini with duck tape.... it's done.

To make it a viable setup, I would invest on making a perfect seal that fits perfectly to Mac Mini's exhaust vent... I will try measure it when I get mine.... then I will make that rubber seal connected to something like this 

Then I can plug this vent into any kind of gigantic fan to suck the shit out of the Mac Mini... don't worry I have three years of apple care for that.

Or... you can just plug this into mac mini exhaust vent LOL

Disclaimer: Do this at your own risk, I am not responsible for your damaged Mac Minis, in particular, parts fell off due to strong winds


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 8:51 pm  

@mac_editor would you therefore be inclined to say that one could use the mac mini (in my case, for gaming, video rendering and audio projects) on a regular basis and still expect a reasonable length of life from the unit (say 4 to 5 years), even if it running consistently in the 80s, possibly 90s?


ReplyQuote
mac_editor
(@mac_editor)
Noble Member Moderator
Joined: 2 years  ago
Posts: 1474
November 9, 2018 9:00 pm  

@expensivefruit Yes I believe you should be fine. If you are still worried, I would say buy AppleCare and then push the machine as much as you like for 3 years straight haha. If its fine after that, then chances are it still will be after 3 more.

purge-wrangler.shpurge-nvda.shset-eGPU.sh
----
Troubleshooting eGPUs on macOS
Command Line Swiss Knife
----
Multiple Build Guides


ReplyQuote
DanHC
(@danhc)
Eminent Member
Joined: 6 months  ago
Posts: 36
November 9, 2018 9:14 pm  

@mac_editor

I still recall what I did about the Macbook Pro Late 2011 with the 6750M GPU on it. I got Apple Care and I overclocked the GPU to play Crysis & other thermal experiment, the board died every two months and I believe I made around 5 repairs / exchange in a year. Apple Care, priceless.


johnjkle and mac_editor liked
ReplyQuote
mac_editor
(@mac_editor)
Noble Member Moderator
Joined: 2 years  ago
Posts: 1474
November 9, 2018 9:23 pm  

@danhc That's nuts haha. None of my Apple products actually have AppleCare. I have just had some tremendous luck with their products. This one time I dropped my iPhone 6 (out of warranty, cracked display), I called Apple and had to wait on the line for 15 minutes (I was willing to pay the 100$ for screen replacement, but the online portal wasn't giving me that option, only the 300$ full replacement option was showing). So 15min into the call regarding this a senior advisor pops up, takes my Apple ID, and orders a next-day air free replacement unit. She said it was special exception. Well. I bet haha.

purge-wrangler.shpurge-nvda.shset-eGPU.sh
----
Troubleshooting eGPUs on macOS
Command Line Swiss Knife
----
Multiple Build Guides


ReplyQuote
johnjkle
(@johnjkle)
Active Member
Joined: 6 days  ago
Posts: 18
November 9, 2018 9:42 pm  

Lol, the AppleCare idea isn't actually that bad - run it care free for 3 years and see what happens :). I'm actually very happy with the performance so far, just a bit worried about long term effects if the temps are hovering at mid 80s a lot. But I also don't really want to stick a vacuum cleaner to the Mini, kinda beats the whole point of it ;). 


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 9, 2018 11:22 pm  

So basically, get AppleCare, run it in to the ground for 3 years and see what happens - sounds like a plan. Maybe even sell it within that period with Apple Care as it will still hold a lot of its value and maybe even upgrade to a new mini that doesn't have these thermal issues, lol.

@danhc lol @ the photos


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 10, 2018 12:56 am  

After asking around on the macrumors forum, one gentleman has stated that using Temperature Gauge Pro he is able to manually control the Mac Mini fan to max RPM (4400) on Mojave. I believe this is a Mac only program, but if someone can run the same test on both Mojave and Windows while using Temperature Gauge Pro to max out the fan RPM in Mojave, we can then compare performance to see whether maxing out the fan RPM solves the thermal issue.


ReplyQuote
(@anethema)
Active Member
Joined: 6 days  ago
Posts: 10
November 10, 2018 1:52 am  

If anyone on here has a 3D printer and a mac mini I would be happy to try to model something a 120mm fan would go on to increase air flow. I would need a good measurement or two but could work off that.


ReplyQuote
Alakiha
(@alakiha)
New Member
Joined: 5 days  ago
Posts: 2
November 10, 2018 8:07 am  

Hi everyone!

Maybe for starter adding something like this under mini would help?

14cm fan running through 5v usb plug!


ReplyQuote
xrim
 xrim
(@xrim)
New Member
Joined: 3 days  ago
Posts: 2
November 10, 2018 6:48 pm  

Hi all, best solution for me (to be made), would be to put the mini outside the original apple enclosure and inside an eGPU eclosure, made on purpose to acomodate one or two GPU´s and the mac mini electronics, with proper air cooled or fanless thermal solution.

Then the mini becomes a nice miniPro.

Imagine, all inside a case like this:


ReplyQuote
(@anethema)
Active Member
Joined: 6 days  ago
Posts: 10
November 10, 2018 8:00 pm  

Can anyone measure the distance here:

I want the distance of the part that actually friction fits into the mac mini base. I will try modelling something that fits a 120mm fan and helps cool it that someone with a 3D printer could try out.


ReplyQuote
(@anethema)
Active Member
Joined: 6 days  ago
Posts: 10
November 10, 2018 9:16 pm  

Ok well barring an actual precise measurement, I tried to measure off of picture. CAUTION: This probably won't fit the mini properly yet.

But this should give you guys an idea of what I was trying to design:

https://www.thingiverse.com/thing:3207891

Another view:

Just to give an idea of the first quick mockup.

The 120mm fan would slot in the bottom there, and get screwed in. The base pieces holds it up and lets air in the corners. The top of the round part would push into the existing mini base, replacing the stock base.

Comments? Suggestions?


theitsage liked
ReplyQuote
Alakiha
(@alakiha)
New Member
Joined: 5 days  ago
Posts: 2
November 10, 2018 9:43 pm  
Posted by: xrim

Hi all, best solution for me (to be made), would be to put the mini outside the original apple enclosure and inside an eGPU eclosure, made on purpose to acomodate one or two GPU´s and the mac mini electronics, with proper air cooled or fanless thermal solution.

Then the mini becomes a nice miniPro.

Imagine, all inside a case like this:

Although by doing that you would lose all the tininess and beauty of Mac Mini but I was thinking about some similar idea! for me it would be great if I could make a custom made CPU block so I can install my own Air/Water cooler.

But maybe for now I should not get ahead of myself! step by by step!


ReplyQuote
James
(@jdstephens)
Active Member
Joined: 10 months  ago
Posts: 11
November 11, 2018 11:14 am  
Posted by: expensivefruit

After asking around on the macrumors forum, one gentleman has stated that using Temperature Gauge Pro he is able to manually control the Mac Mini fan to max RPM (4400) on Mojave. I believe this is a Mac only program, but if someone can run the same test on both Mojave and Windows while using Temperature Gauge Pro to max out the fan RPM in Mojave, we can then compare performance to see whether maxing out the fan RPM solves the thermal issue.

I second this request please!


ReplyQuote
xrim
 xrim
(@xrim)
New Member
Joined: 3 days  ago
Posts: 2
November 11, 2018 12:30 pm  

Yes, I know. If you need and eGPU then the "tininess and beauty of Mac Mini" is already lost.


ReplyQuote
jangoloti
(@jangoloti)
Active Member
Joined: 5 days  ago
Posts: 19
November 11, 2018 1:08 pm  
Posted by: xrim

Hi all, best solution for me (to be made), would be to put the mini outside the original apple enclosure and inside an eGPU eclosure, made on purpose to acomodate one or two GPU´s and the mac mini electronics, with proper air cooled or fanless thermal solution.

Then the mini becomes a nice miniPro.

 

I would just do a Hackintosh in that case.


ReplyQuote
jangoloti
(@jangoloti)
Active Member
Joined: 5 days  ago
Posts: 19
November 11, 2018 3:51 pm  
Posted by: Alakiha

Hi everyone!

Maybe for starter adding something like this under mini would help?

14cm fan running through 5v usb plug!

Why not a cooler blown by a big diameter fan stuck with thermally conductive paste on top of the Mac Mini itself? Being a big metal surface that is blown by the internal flow it would help (a bit) reaching the thermal load without affecting any internal components set point...

Something like this:


ReplyQuote
joevt
(@joevt3)
Estimable Member
Joined: 1 year  ago
Posts: 234
November 11, 2018 5:01 pm  
Posted by: anethema

I want the distance of the part that actually friction fits into the mac mini base. I will try modelling something that fits a 120mm fan and helps cool it that someone with a 3D printer could try out.

The base plate has a diameter of 166.7 mm. But it's not friction fit. The base plate has three non-circular holes at 2 o'clock, 6 o'clock, and 10 o'clock in your picture, that snap onto the three raised screws of the base. The hole edge is 2.65 mm from the base plate edge. hole diameter: 4.9 mm (tangent to base plate circumference) and 4.5 mm (perpendicular to base plate circumference).

The triangle edge distance for the three screws (center to center) is 136.4 mm approximately.

The hole in the bottom of the Mac Mini has a diameter of 169.0 mm. It has a depth of 3.0 mm. I think there's a curved radius of 1 mm (such that the full depth is not all 169.0 mm). The distance between the edge of the hole and the air intake holes is 10 mm.

The stem of the screw is 3.47 mm diameter. The head of the screw is 4.56 mm. Screw height 2.6 mm. Screw head height 1.3 mm. Screw stem height 1.3 mm.

The Mac mini is 197.07 mm square. A larger fan works if you go outside the base plate circle.

There are a few options for attaching your fan adapter to the mac Mini
1) Use the same snap on method as the base plate.
2) Create holes in the fan adapter for the existing screw stems (3.47 mm), then use the existing screws to attach.
3) Friction fit with the 169 mm hole - or make it loose and let gravity hold the mac Mini on top of the fan adapter.


goalque and theitsage liked
ReplyQuote
(@anethema)
Active Member
Joined: 6 days  ago
Posts: 10
November 11, 2018 5:28 pm  

awesome. i can do some modelling and have a printer ut wont have a mini though so would need someone else with a mini and a printer do some testing.


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 11, 2018 8:38 pm  

Awesome work @anethema ! I do not have a 3D printer unfortunately but I did see someone on the original thread who said they had one and would be willing to give it a go. When I get my mac mini I'd be happy to send the design to a 3D print service and give it a go. Are these things usually expensive to print?


ReplyQuote
bluetech
(@bluetech)
Active Member
Joined: 2 weeks  ago
Posts: 7
November 12, 2018 12:58 pm  
Posted by: anethema

Can anyone measure the distance here: 

I want the distance of the part that actually friction fits into the mac mini base. I will try modelling something that fits a 120mm fan and helps cool it that someone with a 3D printer could try out.

Mac mini  2018
The Diameter is 165 mm


theitsage liked
ReplyQuote
(@anethema)
Active Member
Joined: 6 days  ago
Posts: 10
November 12, 2018 4:36 pm  

Awesome I was close! I did 165.44mm haha


bluetech liked
ReplyQuote
bluetech
(@bluetech)
Active Member
Joined: 2 weeks  ago
Posts: 7
November 12, 2018 5:21 pm  

Yes, very very close 🙂  

At plastic 0.44mm is "noting", I guess.


ReplyQuote
expensivefruit
(@expensivefruit)
Eminent Member
Joined: 2 weeks  ago
Posts: 29
November 12, 2018 7:30 pm  

For those of you who may be interested, there is a very interesting discussion on this topic in this macrumors forum with a lot of people sharing their thoughts. It gets particularly tasty around pages 3 and 4. I have three takeaways from the discussion:

a) Although it's not desirable, the CPU is designed to withstand and operate under these high temperatures and that, historically, Apple's record when it comes to CPU failures is very low (if non-existent).

b) Even if one found a DIY solution to cool the CPU, the CPU is designed (supposedly) to simply use the thermal headroom to go even faster until it reaches the ceiling again. You have to put the mini in a freezer until it eventually reached its theoretical turbo speed limit. 

c) As others on here have also suggested, just buy AppleCare. This is the best thermal solution because you're insuring the Mac Mini for 3 years even if you decide to run the god damn thing into the ground. It is also only 99 quid in the UK, which is very cheap when you consider that it is 399 for the new MBPs!

 


bluetech liked
ReplyQuote
Page 1 / 2 Next