Apple confirms coil whine is expected behavior in MM

Nihilvor

macrumors member
Jan 25, 2010
78
4
wow I really didn't think and SSD would make noise.
I don't hear anything with my I3 Mac Mini. It's really calm and much quieter than my Imac. Apple may be telling people who call that it's an expected issue, but many people don't have these issues.

From past experience, Apple will usually replace the unit for you if it bothers you enough, despite what they're saying to discourage replacements. Then, it's the luck of the draw.
 

wgs84

macrumors newbie
Dec 13, 2019
2
0
Bringing this old thread back to life...

I just got an i7 8GB 1TB 2018 Mac Mini - with coil whine right out of the box. Very frustrating. Coincidentally, I also have an i5 8GB 256GB 2018 Mac Mini for work sitting here, too. The i5 doesn't make a sound.

Is something about the i7 the noise culprit?

I reached out to Apple tech support. They had me reset the SMC - then after that didn't fix it, said it was a hardware issue and told me to return it. I'm doing an exchange with the vendor I bought from.
 

russell_314

macrumors 6502a
Feb 10, 2019
738
1,067
USA
Bringing this old thread back to life...

I just got an i7 8GB 1TB 2018 Mac Mini - with coil whine right out of the box. Very frustrating. Coincidentally, I also have an i5 8GB 256GB 2018 Mac Mini for work sitting here, too. The i5 doesn't make a sound.

Is something about the i7 the noise culprit?

I reached out to Apple tech support. They had me reset the SMC - then after that didn't fix it, said it was a hardware issue and told me to return it. I'm doing an exchange with the vendor I bought from.
I have an i7 MM and unless I put my ear against the top I don’t hear any whining.
 

ActionableMango

macrumors G3
Sep 21, 2010
9,510
6,738
wow I really didn't think and SSD would make noise.
They typically don't. This problem is real, but it is also very much "your mileage may vary".

My Airport Extreme coil whine was so bad I could hear it in an adjacent room. But most Airport Extremes did not experience this at all.
 

frou

macrumors 6502a
Mar 14, 2009
689
759
Reading the term Coil Whine always causes me to pause and think. It would never even enter my head to describe it as Whine... it's BUZZ!

Virtually every graphics card I've ever owned has done it when being worked hard.
 
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wgs84

macrumors newbie
Dec 13, 2019
2
0
More testing here since I have 2 side by side to compare. The noise I'm hearing is associated with drive read/write operations. I did stress testing of CPU and SSD. The noise follows SSD operations. CPU stressing didn't create the noise - and eventually the fan kicked in which then becomes the dominate noise source.

The stress test doesn't create the loudest noise, either. Boot up and other activities create more SSD noise. Maybe that has to do with the randomness of a bootup vs the repeated SSD task done by Disk Speed Test.

Interesting side note from my comparison testing - maybe this is documented elsewhere - the i5 256GB drive has write speeds around 1300 MBps. The i7 1TB drive has write speeds around 2700 MBps. Both have similar read speeds of 2600 MBps.

The i5 does have some subtle noise - I previously thought it was silent. The i7 is certainly more noticeable. Either because of a problem...or that's just the way it is.
 

Boyd01

Moderator
Staff member
Feb 21, 2012
4,243
1,905
New Jersey Pine Barrens
maybe this is documented elsewhere - the i5 256GB drive has write speeds around 1300 MBps. The i7 1TB drive has write speeds around 2700 MBps. Both have similar read speeds of 2600 MBps.
The fact that large SSD's have faster write speeds has been well documented. Somebody with more tech knowledge than I can explain it better, but I think it has to do with the memory cells being closer together on larger drives.

But I remember reading about this in 2013 when Apple put the faster interface in the MacBook Air, and the top of the line 512gb model had much higher write speeds than the basic 128gb model, but the read speeds were more similar.

BTW - that's a great username WGS84! (I make maps at boydsmaps.com). :)
 

Tesla1856

macrumors member
Jul 25, 2017
73
22
Texas, USA
More testing here since I have 2 side by side to compare.

The i5 does have some subtle noise - I previously thought it was silent. The i7 is certainly more noticeable.
The Intel-i7 is likely pushing the (small , barely adequate) power-supply into a new high-utilization range. SMPS are not as stable as they reach max-output, and that power is not as "clean". This can cause coil-wine in power-supply and other components. That is why you always over-size the PS (not under-size it so it can fit in a tiny box and look pretty).

But before I would say it is definitely "coil wine" and not just EMF/EMI ... I would have to physically disconnect the internal speaker.
 

Tijs

macrumors newbie
Jan 19, 2012
10
4
I picked up a stocked I7/256/16/10Gbe today from a reseller. While the fan noise is very faint (which I love) the HDD sound this SSD makes is a bit irritating. It sound exactly like an old 2.5 laptop HDD searching but less loud. It is easily noticeable by opening safari and surf to a website. While loading the site it will make the noises. Also when booting and when I did the software update it is very prominent.

My girlfriend only hears it from about 10cm away from the unit. I can hear it clear at 1-2m distance even with background noise present so for sure it has something to do with the condition of ones ears and the ability to focus on a specific sound as well (I produce music with my Macs). That said my samsung sata SDD drive in my MBP doesn't make a sound at all so I think they cheaped out on this part and it should be considered as a design fault if you ask me. Especially because of it's premium status.

From what I read I think that swapping it for another one will not solve this issue if you've sensitive ears. I'll do some more testing coming days (maybe it will faint down after indexing) and will decide wether I can live with this or not. Fortunately I come for the era where I used to have PC's, with lot's of fan and HDD noise even my MBP 2011 came with a noisy HDD and when I just got that, it was not even a point of attention. In that perspective this thing is a dream noise wise.
 

Tijs

macrumors newbie
Jan 19, 2012
10
4
After some more testing I found that switching the sample rate of my Apollo twin x to 96 kHz induces a higher pitched tone from the Mac mini itself (not over speakers) which get interrupted by the ssd hdd sound. Changing buffers from 512 to 236 and 128 gives the tone a different pitch.
My brother who has the 16 inch mbp can also reproduce this pitched whiney tone in his MBP by switching his interface to 96 kHz but does not hear the hdd sound.

The more I read about it, people swapping units five times with same results and not able to reproduce it in stores, the more I think this is a power line issue in my and their homes making these electric noise become more pronounced. It might be there in minimum amounts on all units, but get amplified by poor mains voltage. I'll try if a good power conditioner can eliminate the sounds coming from the mini case.

EDIT:

One more addition also. on the internal sound card you can make the " SSD/ HDD"-sound more loud by opening up a DAW session and load it full of (CPU based. ruling out ssd use ) plugins with each increase of the CPU meter in Ableton the mini starts screaming harder and its exactly that hdd sound. This makes me think it's not an SSD issue but more of a CPU load issue. Definitely not coming from speaker as it's the same with the Apollo vs internal audio. This also explains that for people who switch off turbo boost, the sound is greatly reduced. I tried Turbo boost switcher but it doesn't seem to work in Catalina 15.2

Regardless of the weird noises, this unit is quite silent with lots of plugins running. The fan stays under 2400 RPM which is a very nice thing. Also the weird noises submerge when music is played over my monitors even on low volume so I think can accept this on the long run.

After my holiday I'll try what happens when booting the OS from a known silent samsung SATA drive via USB bracket. If the noise still persists then and gets higher with pushing the CPU in Ableton I think it has to be the CPU load then causing this sounds, or maybe the voltage supply in general. Which makes me wonder: is booting a CPU heavy task as well, because it's really noticeable then?
 
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Tijs

macrumors newbie
Jan 19, 2012
10
4
I’ve found a way to eliminate the coil whine when present. The coil whine has nothing to do with ssd’s as a lot of topics here suggesting. It has to do with CPU power regulation as the topicstarter already pointed out in this topic.Probably all Multicore 8th gen intel cpu’s suffer from this problem to some extend.

To make it very apparent: load your cpu to about 40% and set your sound output to 96 khz. Another way is to go to About my mac and go to the storage tab.

To eliminate it: download Intel Power Gadet , go to the menu tab Test and run “all thread test” it will run your cpu at full wattage,full frequency, and full utilization. Remarkably while power gadet and activity monitor shows full cpu utilization , all the headroom from your CPU is still available for the programs you’re running.

Of course you cpu will get hotter and the fans will be more audible after a while but it proves that it really has something to do with power fluctuations on the cpu as opposed to the ssd. It’s a probably a combination of poor quality VRM ‘s on the motherboard and speedstep fluctuations. I think apple/intel really should adress this issue as it was non existant on older generations. Another example of the eco movement go wrong :cool:
 

Spungoflex

macrumors regular
Oct 30, 2012
170
50
I’ve found a way to eliminate the coil whine when present. The coil whine has nothing to do with ssd’s as a lot of topics here suggesting. It has to do with CPU power regulation as the topicstarter already pointed out in this topic.Probably all Multicore 8th gen intel cpu’s suffer from this problem to some extend.

To make it very apparent: load your cpu to about 40% and set your sound output to 96 khz. Another way is to go to About my mac and go to the storage tab.

To eliminate it: download Intel Power Gadet , go to the menu tab Test and run “all thread test” it will run your cpu at full wattage,full frequency, and full utilization. Remarkably while power gadet and activity monitor shows full cpu utilization , all the headroom from your CPU is still available for the programs you’re running.

Of course you cpu will get hotter and the fans will be more audible after a while but it proves that it really has something to do with power fluctuations on the cpu as opposed to the ssd. It’s a probably a combination of poor quality VRM ‘s on the motherboard and speedstep fluctuations. I think apple/intel really should adress this issue as it was non existant on older generations. Another example of the eco movement go wrong :cool:
This does not sound like a good solution.
 

Tijs

macrumors newbie
Jan 19, 2012
10
4
This does not sound like a good solution.
Indeed, a good solution would be for intel and apple to adress this issue. It’s more of a proof point that is related to the cpu power management and not to the ssd as many here and on the internet are thinking. It does not matter if you order one with 128-256-512 , its simply not related to that.
I also would not advise this as a solution to the problem as it will probably wear out your cpu faster. Just accepting the coil/vrm whine is the best option for this problem.
 
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Reflej0

macrumors member
Jan 3, 2020
78
27
Hi, with a 2018 Mini I5 I don't suffer that problem either.
Anyway, I have permanently (personally configured) the fan always at 4000rpm so the fan noise was louder.
I think the disagreement you raise is more because Apple assumed to have the problem and do nothing than the problem itself.
 

Spungoflex

macrumors regular
Oct 30, 2012
170
50
Indeed, a good solution would be for intel and apple to adress this issue. It’s more of a proof point that is related to the cpu power management and not to the ssd as many here and on the internet are thinking. It does not matter if you order one with 128-256-512 , its simply not related to that.
I also would not advise this as a solution to the problem as it will probably wear out your cpu faster. Just accepting the coil/vrm whine is the best option for this problem.
Makes sense that it's a CPU issue as I've read similar complaints about the Intel NUC mini PCs with 8th gen CPUs.