How to fix my Mac mini heating up in sleep mode?

It is a fact that my mds_stores were writing excessively to disk and many other people have been reporting this since July.

The OP has not found a solution to his problem so I suggested this as something worthy of consideration as he has probably not read my thread.

The whole danger with what I suggested is that it is a silent killer . . . there is no sign anything is amiss unless you run DriveDX or watch Activity Monitor which most Mac users do not do.

I have disabled Spotlight search as shown below and now the writes are down to a normal level.

MobileMeKevin wrote:

Are you suggesting shutting down an M4 Mac mini or newer Mac nightly? That contradicts Apple’s recommendation, which is to let the Mac sleep unless you'll be away for an extended period.

... daily shutdowns aren’t aligned with Apple’s guidelines.

Please tell us where Apple may have documented those guidelines & recommendations. I have never seen them.

Frequent shutdowns can cause unnecessary wear on components.

Urban myth. While there "may" have been an argument for this when traditional hard drives were in play, in this era of SoC's and SSDs there is nothing to wear.

Three days ago I discovered my M2 mini running Sequoia 15.1 was writing excessively to disk.

It had written about 4 months of data (1.2 TB) in a fortnight!

An internet search revealed it to be quite common and causing dangerous wear especially to small or cheap SSDs.

There is no sign of this excessive writing, nothing appears on your drive nor is there any impact on performance.

It might be worth checking in Activity Monitor to see whether your Mac is affected as it could be causing the heat during sleep.

It's a Spotlight bug which has been there since Ventura and Sonoma. Apple must definitely be aware of it, because it has been written about many times both here and on Reddit. I myself have this bug on my production Mac with two external SSDs connected. I disabled Spotlight via terminal, after first disabling System Integrity Protection. The writing stopped. It's a bug.

[Edited by Moderator]

I had the same issue with my M4 Mac Mini (512GB): it would get hot when not being used, but it would be cool when actively being used. I tried many recommendations in this thread and tested them out, including a factory reset, but the issue continued to happen. The one thing I did not try was disabling spotlight search, but I use Spotlight very frequently, so that wouldn’t really work as a solution for me.

I called Apple Support and they recommended to bring it in to a store for a diagnostic. I did that, they kept it for 3 days, then concluded the hardware was fine and recommended another factory reset.

In the end I decided to return the Mac Mini and go back to my 14” M1 MacBook Pro, which still runs perfectly. Bummer, as I really liked the form factor of the Mini and was excited to have a dedicated desktop computer for the Studio Display. However, I had concerns for the longevity of the device with this issue going on, so the return option was the best choice for me. Hopefully this issue can be acknowledged and fixed in the future.

Turn On "Prevent automatic sleeping when display is off"

Set "Turn display off when inactive" to 5 or 10 minutes.

Then leave the Mac mini On with the display Off and only shut down for long periods of non-use.

Sleep is unnecessary on later Macs and should be disabled. Shut for long absences/idle overnights i.e and for regular operation, use the settings exactly as shown by @den.thed. Important: do not manual-sleep: leave on or shut down.

Are you suggesting shutting down an M4 Mac mini or newer Mac nightly? That contradicts Apple’s recommendation, which is to let the Mac sleep unless you'll be away for an extended period. Overnight doesn’t count as a long period. Apple even designed the M4 Mac mini’s power button placement with minimal use in mind. Frequent shutdowns can cause unnecessary wear on components. While powering down is reasonable for weekends or longer absences, daily shutdowns aren’t aligned with Apple’s guidelines. Could you clarify why you recommend this approach?

Turn off "Low Power Mode"

Turn on "Prevent automatically sleeping when the display is off"

Then test for a couple of days.

To reach out directly to Apple, please send Feedback and contact Apple Support.

Feedback - Mac mini - Apple

Official Apple Support

How hot is it getting?

Is it just warm to the touch or hot?

What are the temperatures of the components? To find out, download the free MacsFanControl.

MacsFanControl

You can then see whether anything is getting too hot.

It is quite likely that the SSD is getting warm because during sleep the fan will not be operating. Once you wake up the fan kicks in at a slow speed and cools the machine down.

I cannot prove that theory but it seems plausible.

MateuszStepien wrote:

Thank you for your reply. There is no other option for it to be in sleep mode though and not heat up?

You're welcome.

Is "Wake for network access" in the Energy Settings turned On...?

If it is, turn it Off and test.

Then if that doesn't help..?

Leave the Mac mini On with the Display(s) Off and Shut Down for longer periods of non-use.

I have a very similar setup and exactly the same encounter of the sleep issue. As I've pointed out before, check the "Low Power Mode" will keep the M4 mini in sleep.

Obviously it's a bug for which Apple has not fixed because not many people noticed this and is not that obvious. However, as a responsible company bragging on environmental credentials, Apple ought to address this issue so that people don't waste unnecessary electricity when the minis are in perceived sleep mode.

I do care about this sleep function. It’s a very important feature. Whether you care or not is not my business. Have a nice day!

Ian R. Brown wrote:

How hot is it getting?

Is it just warm to the touch or hot?

Those are excellent questions Ian.

What are the temperatures of the components? To find out, download the free MacsFanControl.

MacsFanControl

You can then see whether anything is getting too hot.

That observation will have to happen quickly after wake from sleep, because the fan would come on when you went to check the temp's.

It is quite likely that the SSD is getting warm because during sleep the fan will not be operating. Once you wake up the fan kicks in at a slow speed and cools the machine down.

I was thinking the power supply, the network card to allow wake for access and who knows what other components are drawing power in computer sleep mode.

I cannot prove that theory but it seems plausible.

Agreed.

I've just tried again with "Prevent" checked and Low Power Mode unchecked. My M4 mini did not go into sleep after a time out period. In fact, it never went into the sleep mode even after 3 hours. It clearly shows that this is a bug, not a faulty operation.