Mac Mini 2012 SSD+HDD heats up really quickly

[rachalmers]

I'm using iStat Menu to watch the system, and Activity Monitor. Since upgrading to an SSD 1TB drive, plus a second internal HDD 1TB drive, I notice the temperatures gor up really quickly, making the fan really speed up. I'm wondering what the System Fan monitor actually watches?

Should I use iStat to control the fan, or just leave it at System Controlled?

or, of these iStat temperatures, which should I watch?

 

[Raz0rEdge]

Is that in degC or degF? If degC, then your CPU Die temp is reaching thermal shutdown temp. Adding an SSD alone should not cause this issue. Who did the upgrade? How were two drives jammed into the cramped space of the Mac Mini?

 

[rachalmers]

It’s oC, and it’s a 2012 July, Mini. Which has two drive bays. Fitting two drives is relatively easy and I did it myself, as I’m quite capable. And I’m asking the question because previously I had two HDDs in there with no heat problems. So I’m wondering if the SSD runs hotter than a HDD in the Same Situation?
The app running up that temp is anything that is processor intensive. Like WoW, or BOINC, running SETI.
I may strip it down again and swap drive positions? Or not.

 

[MacInWin]

It's not the drives, they are showing at 35 and 31. Something is pounding the CPU. I'd suggest you run Activity Monitor all the time for a while and when the temps take off, see what is driving the CPU hard. You can sort the CPU view by CPU% to get the heavy hitters to the top of the list.

 

[Raz0rEdge]

Are you suggesting that running CPU intensive apps (like the ones you listed) prior to the SSD didn't cause this sort of temp hike? If so, remove the SSD to see if the temps are stable with the intensive applications.

 

[ferrarr]

Maybe one of the fans?? isn't connected? Download Macs Fan Control, Macs Fan Control - control fans on Apple computers, also on Windows via Boot Camp, and see if they are powered?

I only have one fan in my Late 2014 mini, but it wasn't working a few months ago, and I had to take it apart again to get it working.

 

[rachalmers]

Ok, thanks folks. I’m going to open it up again. I can’t remember if the cpu has a heat sink on it or not.? But it is a result of intensive cpu work, so I need to cool that.
I use iStat for the fan, or interchangeable the System fan control.


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[Raz0rEdge]

I don't believe there is a heat sink on the CPU, so it's the strategic placement of the fans that allow for cooling. If are using CPU intensive apps and the fans aren't running (audibly) at high speeds, then you are not going to get much cooling and the situation you are in. I would investigate the fans and also ensure that there aren't any blockages of dust or anything.

 

[rachalmers]

I don't believe there is a heat sink on the CPU, so it's the strategic placement of the fans that allow for cooling. If are using CPU intensive apps and the fans aren't running (audibly) at high speeds, then you are not going to get much cooling and the situation you are in. I would investigate the fans and also ensure that there aren't any blockages of dust or anything.

Actually, there is a heat sink...
Mac mini Late 2012 Heat Sink Replacement - iFixit Repair Guide

So maybe I'll re-grease the heatsink, maybe not. Maybe I'll just stop doing CPU intensive work...

 

[Raz0rEdge]

Hmm, must have sailed past that section of the teardown, I jumped right to the CPU part last time. However, if replacing the drive does require you to remove the heat-sink, then it's entirely possible that the re-attachment is the issue whereby the grease isn't doing what it needs to. Re-greasing it should definitely help.

 

[iggibar]

I'm using iStat Menu to watch the system, and Activity Monitor. Since upgrading to an SSD 1TB drive, plus a second internal HDD 1TB drive, I notice the temperatures gor up really quickly, making the fan really speed up. I'm wondering what the System Fan monitor actually watches?

Should I use iStat to control the fan, or just leave it at System Controlled?

or, of these iStat temperatures, which should I watch?

View attachment 29589

A few things to mention.

1. Let your computer do the fan control. No need to have a separate program accessing critical data and having permissions to override critical system operating parameters. You computer is more than capable of controlling its own fans if it detects high temps, even if you don't like how it's running.
2. All temperature readings are important, and it's important to know their normal operating range.
3. Your Mac Mini was capable of using 2 HDDs, but most likely with one stock. You have to figure you're cramming an HDD's worth of extra stuff in your Mac Mini, and are taking up that space that would allow for air to flow more freely. By restricting air flow, you are going to cause temperatures to go higher on this cooling system that is technically laptop-grade.

How have you installed OSX and the programs across the two drives?

 

[ferrarr]

Also, a faster spinning hard drive, will create more heat, than the slower speed versions.


Bob -

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[iggibar]

There's hardly any negligible heat difference between the SSD and HDD though. The temperature spike is throughout all cores, and resonates around the CPU die. That means whatever is causing the CPU to do so much work is keeping it on a long time. That's why it's good to know how OSX and programs are installed and used across both drives. Depending on what file is kept running across the system might determine buss, cores, or channels are needed to keep it running. This happens sometimes on the tower Mac Pros when users scatter data across all HDD bays. The processor is kept running for the DUMBEST kernel thats running in the background of a program that is found in another HDD away from the OS HDD.

 

[rachalmers]

Well that was fun.
I stripped it down, lifted the heat sink and... OMG.
The ancient paste that was there was in a patchy blob, hardened to a cement like patch that just flaked offwhen I touched it.
So, cleaned with the Arctic spodger, rubbed back with alcohol that was supplied with the paste, and admired the new shiny surfaces.
Carefully spread the thinnest coda of new heat sink paste on one surface and put it all back together.
What a mission. Not for the faint hearted, but fortunately I’ve done it 4 times now. 3 for drives and now one for heatsink.

Is it running cooler? You bet you sweet life it is. I’ve even left BOINC running the SETI job while I go out. I want to see if it’s ok when I return.

Would I recommend replacing the heatsink paste if you’ve never done it? Certainly. But it’s a really difficult task. If you have no hardware experience, don’t even think about it. Get an Apple tech to do it. That way hopefully if they break it, you may be covered. Ask first.

So all is well down on the farm...

 

[iggibar]

Well that was fun.
I stripped it down, lifted the heat sink and... OMG.
The ancient paste that was there was in a patchy blob, hardened to a cement like patch that just flaked offwhen I touched it.
So, cleaned with the Arctic spodger, rubbed back with alcohol that was supplied with the paste, and admired the new shiny surfaces.
Carefully spread the thinnest coda of new heat sink paste on one surface and put it all back together.
What a mission. Not for the faint hearted, but fortunately I’ve done it 4 times now. 3 for drives and now one for heatsink.

Is it running cooler? You bet you sweet life it is. I’ve even left BOINC running the SETI job while I go out. I want to see if it’s ok when I return.

Would I recommend replacing the heatsink paste if you’ve never done it? Certainly. But it’s a really difficult task. If you have no hardware experience, don’t even think about it. Get an Apple tech to do it. That way hopefully if they break it, you may be covered. Ask first.

So all is well down on the farm...

Sweet, but doesn't that mean you should've had this issue before as well? Regardless, upgrading thermal paste is always a great thing to do to increase the life and thermal limit of any computer.

Unless you count custom computer builders, most computer manufacturers have never been known for using the highest quality thermal paste. I noticed a large enough difference each time upgrading thermal pastes on my trash can and tower Mac Pros. Gives me a bad feeling knowing how much some of these pastes degrade over time, and that most people are not able to do anything about it themselves.

 

[rachalmers]

Sweet, but doesn't that mean you should've had this issue before as well? Regardless, upgrading thermal paste is always a great thing to do to increase the life and thermal limit of any computer.

Unless you count custom computer builders, most computer manufacturers have never been known for using the highest quality thermal paste. I noticed a large enough difference each time upgrading thermal pastes on my trash can and tower Mac Pros. Gives me a bad feeling knowing how much some of these pastes degrade over time, and that most people are not able to do anything about it themselves.

Yes, I'm pretty sure I did have this problem before, but chose to ignore it. It wasn't as bad though as after I replaced the main HDD with the new SSD. Previously it had only overheated under fairly strong CPU load. But this time, any work made it spin up the fan and it really began to annoy me.
So between the teardown, which resets the SMC anyway, and the new thermal goo, it's solved probably a few other issues as well.
It now runs BOINC on a 50% load with no appreciable fan spinup. I can also run World of Warcraft in Window mode, with no appreciable spinup.
And this is on a system running an Apache webserver, and a Postfix+Dovecot etc mailserver, mysql etc etc.
At idle - no Boinc, no Wow, its sitting on 58C, at 1802 rpm under System Control of the fan.

I agree with you about the bad paste problem. This box is late 2012. So assuming that it was actually made in that year... then that paste such as it was is 6 years old. For the looks of it I'd say it should have been replaced if not immediatly on delivery, certainly soon after. But in any case, it probably should be replaced at least every couple of years.

I don't know what the new Mac Minis are like, I don't have one. I'm not real impressed with thier specs to be honest. I like the 2012 model because it is at least upgradable to some decent specs. Adding that second drive, HDD or SSD, and adding max RAM to bring it up to 16GB. I could be wrong, but I believe you cant do that with the new ones.???

So in summary. If the Mac is older than a year - and out of warrenty change that paste. Put new goo in, and breath some new life into the machine.

 

[iggibar]

Glad your problem is sorted