Mac Mini 256GB SSD users: How is your experience running MacOS from an external drive?

[LelandHendrix]

This thread is titled: "Mac Mini 256GB SSD users: How is your experience running MacOS from an external drive?" . . . are you confident in your assertion: " . . . it’s never a clear win for performance on Apple Silicon running macOS on external SSDs regardless of internal SSD."

A reminder: (from a reddit thread - other mini M4 256GB owners may agree/disagree):

View attachment 2466542

I get your point. And there may be advantages in convenience in some cases and on base config 256 models perhaps you are right about performance in very rare use cases involving long sustained continuous writes like recording video and multitrack audio? I just suspect you're not going to exceed that read speed you just posted for internal 256 while using thunderbolt 4. Though the write speed may be bested conditionally, you will suffer from a tiny bit of extra overhead utilizing the controller chips within the pipeline to your external drive vs internal.

For reference, I just tested a top-tier performance 4TB SSD in one of the best enclosures for thunderbolt 4:

And just for giggles here is the M4 Pro internal:

 

[shoarthing2]

The OWC 1M2 is advertised as an USB4, rather than a TB4, drive. To those who have been using it as an external Mac OS boot drive, does it work well? Any problem? Any other better enclosure?

The 1M2 is relatively massive (about 250gr/over 8oz) & deeply-finned, to deal with the heat-output of a gen4 NVME (up to a max of around 8W) plus the output of its USB4 controller; an Asmedia ASM2464PD (around 2 to 3W). You'll see from this interior view that the underside of the finned top-casting has plural heatpads, one from the NVME, another from the controller:

. . . another & considerably cheaper fanless USB4 enclosure using the ASM2464PD, also deeply-finned & of around 250gr/over 8oz mass, is the Colorii (also sold by Hagibris, & in the recent past by Qwiizlab) MC40 - you'll see from this interior view that it too makes explicit provision to route the heat of both NVME & controller to the underside of its deeply-finned top casting:


. . . there are many other designs of ASM2464PD-based enclosures; but this above combination of mass, fin area, & care over heatpaths seems at present to offer the best functionality for an external under continuous use.

This post (in a long thread devoted to Thunderbolt enclosures) gives an idea of the performance of a MC40 with a decent DRAM-cache 4TB NVME.

 

[LelandHendrix]

For those successful “bulletproof” experience, do they keep the Mini on all the time? I think somebody mentioned that their external SSD got disconnected during sleep and had trouble getting it reconnected automatically during wake from sleep.

It's still not uncommon with some thunderbolt docks/hubs, fishy cables, etc. Of course for system drive purposes you'd want a direct and singular connection.

 

[DaveFromCampbelltown]

This thread is titled: "Mac Mini 256GB SSD users: How is your experience running MacOS from an external drive?" . . . are you confident in your assertion: " . . . it’s never a clear win for performance on Apple Silicon running macOS on external SSDs regardless of internal SSD."

A reminder: (from a reddit thread - other mini M4 256GB owners may agree/disagree):

How fast is the M4 Mac Mini running from an external drive?

I thought I would put down a few results from real-world stuff that I do with my M4 Mac Mini.

	Internal Drive	Samsung T7	Samsung T3	Fusion Drive
Booting Up	12 sec	14 sec	27 sec	46 sec
Load LibreOffice	2.5 sec	2.6 sec	6.8 sec	3.9 sec
Load MS Word	2 sec	2.4 sec	9.9 sec	4.2 sec
Compile Bible to ePub	7 sec	7.6 sec	8.1 sec	8.0 sec
BlackMagic Speed	4k/3k MB/s	770/730 MB/s	390/370 MB/s	400/360 MB/s

Notes:

1. There is little effective difference between the Internal Drive and the Samsung T7, when the latter is plugged into one of the Thunderbolt ports at the back of the Mac Mini. This is because the overhead of doing stuff (loading the OS and applications, processing data) is greater than the overhead of accessing the drive.
2. Boot up times were measured from the startup “Bong” to when the desktop appeared.
3. Loading the large applications LibreOffice and MS Word were the first loading after boot up, so no caching was involved.
4. Compile the Bible to ePub. I have a LaTeX file of the text of the bible. It is 5.9 Mbytes in size. I then used Pandoc to convert that LaTeX file to an ePub file of 1.9 Mbytes. This is an operation that happens almost entirely in RAM, so there is little effective difference in processing speed, no matter what drive it is working off.
5. A fusion drive is a complex affair which takes some days of use to ‘condition’ itself, so that the most-used files are on the SSD and the rest are on the HDD.
6. The BlackMagic Speed just gives you an idea of the basic speed of the drive.
7. I am not a great fan of benchmarks. You can see that there is little relationship between the benchmarked speed of the drive via BlackMagic and the real world performance of certain tasks.

 

[shoarthing2]

How fast is the M4 Mac Mini running from an external drive?

I thought I would put down a few results from real-world stuff that I do with my M4 Mac Mini.

	Internal Drive	Samsung T7	Samsung T3	Fusion Drive
Booting Up	12 sec	14 sec	27 sec	46 sec
Load LibreOffice	2.5 sec	2.6 sec	6.8 sec	3.9 sec
Load MS Word	2 sec	2.4 sec	9.9 sec	4.2 sec
Compile Bible to ePub	7 sec	7.6 sec	8.1 sec	8.0 sec
BlackMagic Speed	4k/3k MB/s	770/730 MB/s	390/370 MB/s	400/360 MB/s

Notes:

1. There is little effective difference between the Internal Drive and the Samsung T7, when the latter is plugged into one of the Thunderbolt ports at the back of the Mac Mini. This is because the overhead of doing stuff (loading the OS and applications, processing data) is greater than the overhead of accessing the drive.
2. Boot up times were measured from the startup “Bong” to when the desktop appeared.
3. Loading the large applications LibreOffice and MS Word were the first loading after boot up, so no caching was involved.
4. Compile the Bible to ePub. I have a LaTeX file of the text of the bible. It is 5.9 Mbytes in size. I then used Pandoc to convert that LaTeX file to an ePub file of 1.9 Mbytes. This is an operation that happens almost entirely in RAM, so there is little effective difference in processing speed, no matter what drive it is working off.
5. A fusion drive is a complex affair which takes some days of use to ‘condition’ itself, so that the most-used files are on the SSD and the rest are on the HDD.
6. The BlackMagic Speed just gives you an idea of the basic speed of the drive.
7. I am not a great fan of benchmarks. You can see that there is little relationship between the benchmarked speed of the drive via BlackMagic and the real world performance of certain tasks.

We all have our own "Real World" tasks . . . . here's a snapshot of migrating a user from one Thunderbolt3 external system drive to a fresh OS install in another external USB4 system drive (on different TB/USB4 buses) . . . you'll see how these NVME SSDs can deal with reading/writing the umpteen, mainly small files that make up an active working installation:

 

[DEMinSoCAL]

I'm intrigued by trying this (running my M4 Mac Mini from external USB4 drive) as there is an issue with MS OneDrive keeping local copy of OneDrive on an external drive (it won't do it...it creates a link on the external and saves the local copy on the system drive where the user folder is and quickly fills the 256GB drive).

My question is, once you have installed macOS on the external, what do you do with the internal drive? Format it and use it for data?
Also, is there any way to transfer the internal contents to the external and the set the external as the boot so as to not have to reinstall and reconfigure everything from scratch?

 

[Alameda]

I'm intrigued by trying this (running my M4 Mac Mini from external USB4 drive) as there is an issue with MS OneDrive keeping local copy of OneDrive on an external drive (it won't do it...it creates a link on the external and saves the local copy on the system drive where the user folder is and quickly fills the 256GB drive).

My question is, once you have installed macOS on the external, what do you do with the internal drive? Format it and use it for data?
Also, is there any way to transfer the internal contents to the external and the set the external as the boot so as to not have to reinstall and reconfigure everything from scratch?

Maybe don’t store tens of gigs of stuff on MS OneDrive?

 

[turbineseaplane]

My question is, once you have installed macOS on the external, what do you do with the internal drive? Format it and use it for data?

So far I've done nothing with it, but it's there in the Finder ready to be used for anything.

It's a bit small for it, but it could be an extra Time Machine drive ... or just an extra place to stash anything you like.

I might make it a downloads folder as I tend to have 30-90GB in downloads as slush at any given time.

 

[turbineseaplane]

Also, is there any way to transfer the internal contents to the external and the set the external as the boot so as to not have to reinstall and reconfigure everything from scratch?

Meaning convert an existing install over to external booting drive only?
That ... I don't know ... and I'd be wary about it working right honestly

 

[DEMinSoCAL]

Maybe don’t store tens of gigs of stuff on MS OneDrive?

Maybe if you don't have something constructive to say, don't say anything?

 

[Mike Boreham]

My question is, once you have installed macOS on the external, what do you do with the internal drive? Format it and use it for data?

I would keep it as an emergency bootable drive to regain control of the machine in case the external decides not to boot one day.

Also, is there any way to transfer the internal contents to the external and the set the external as the boot so as to not have to reinstall and reconfigure everything from scratch?

Boot to Recovery, with prepared external connected. Install macOS onto the the external. When Setup Assistant starts (which it will, now booted from the external) choose migrate from the internal.

 

[DEMinSoCAL]

I would keep it as an emergency bootable drive to regain control of the machine in case the external decides not to boot one day.

Boot to Recovery, with prepared external connected. Install macOS onto the the external. When Setup Assistant starts (which it will, now booted from the external) choose migrate from the internal.

You're a genius.

I've ordered an enclosure and look forward to trying this out. For migrating my existing internal to the external, would it work as well to create a macOS USB installer and boot from that instead of Recovery boot?

 

[hajime]

Does booting the OS from an external drive make the overall system less secure? I think when M1 was released, there was some kind of T1-security chip connected to the internal SSD to make it more secure. Now that we have the OS installed on an external SSD without connection to that security chip, does this make they system less secure?

 

[shoarthing2]

Does booting the OS from an external drive make the overall system less secure? I think when M1 was released, there was some kind of T1-security chip connected to the internal SSD to make it more secure. Now that we have the OS installed on an external SSD without connection to that security chip, does this make they system less secure?

Yes (see previous). You're outside the 'Secure Enclave' of auto-encrypted everything thanks to the T2. You need to enable Filevault on the external (see previous) & there is a performance cost - an endurable one. AND there's physical security concerns for the external (esp. if not encrypted).

 

[Mike Boreham]

For migrating my existing internal to the external, would it work as well to create a macOS USB installer and boot from that instead of Recovery boot?

Yes that should work but no advantage unless you were going use the installer on multiple machines (saving downloads) or wanting to install an older version of macOS.

 

[hajime]

Yes (see previous). You're outside the 'Secure Enclave' of auto-encrypted everything thanks to the T2. You need to enable Filevault on the external (see previous) & there is a performance cost - an endurable one. AND there's physical security concerns for the external (esp. if not encrypted).

I am more concern about cyber attacks. Am I worrying too much? I just use the computer at home so I am not concerned about physical security.

I have two options:

1. Keep the Mini M4 16-512 and move the home folder to an external drive. This approach has some problems and make file management more complicated than having everything on the external drive.

2. Return it and get a Mini M4 16-256 and boot the OS from an external drive.

As for performance cost, I ordered an OWC 1M2 and Samsung 990 Pro 4TB. The combo should be faster than the internal 256 or 512 SSD of the Mini M4.

 

[shoarthing2]

. . . . As for performance cost, I ordered an OWC 1M2 and Samsung 990 Pro 4TB. The combo should be faster than the internal 256 or 512 SSD of the Mini M4.

This above combo will be faster than the base 256GB SSD M4 option (as per your title to this thread); but all-in-all not as fast as the 512GB SSD. On the bright side, you'll have 4TB of space & a large DRAM-cache, in which will take place much of your IO activity.

 

[hajime]

I think under Mac OS, one could encrypt an external drive too. I guess it means also the external boot drive. So how could booting from an external drive makes the system less secure?

 

[shoarthing2]

I think under Mac OS, one could encrypt an external drive too. I guess it means also the external boot drive. So how could booting from an external drive makes the system less secure?

It might be a good idea to start here: . . . then make your decisions re: security. Current Mac hardware + OS X provide sufficient tools.

 

[hajime]

Thanks for the link. In the article, the author wrote: "Whether your Mac has a T2 or Apple silicon chip, it’s designed to boot securely, which means that every stage of the boot process, from its Boot ROM to running the kernel and its extensions, is verified as being as Apple intends. To ensure that, your Mac should run at Full Security. For a T2 model, that means disabling its ability to boot from external disks; for an Apple silicon Mac, that means no third-party kernel extensions. "

In the last sentence, he mentioned that for T2 model, disable the ability to boot from external disks but when he mentioned about Apple silicon Mac, he only wrote no third-party kernel extensions. So for the Mini M4, we don't need to disable the ability to boot from external disks and can go ahead to boot from an external drive?

 

[shoarthing2]

Thanks for the link. In the article, the author wrote: "Whether your Mac has a T2 or Apple silicon chip, it’s designed to boot securely, which means that every stage of the boot process, from its Boot ROM to running the kernel and its extensions, is verified as being as Apple intends. To ensure that, your Mac should run at Full Security. For a T2 model, that means disabling its ability to boot from external disks; for an Apple silicon Mac, that means no third-party kernel extensions. "

In the last sentence, he mentioned that for T2 model, disable the ability to boot from external disks but when he mentioned about Apple silicon Mac, he only wrote no third-party kernel extensions. So for the Mini M4, we don't need to disable the ability to boot from external disks and can go ahead to boot from an external drive?

As previously linked-to in this thread; Apple Support have a Howto. For many, it is forbidden within their work-practices to keep unencrypted data . . . for those, if you boot an Apple Silicon mac off an external drive, you will need to enable some means of full-volume encryption . . . the simplest/easiest means is Filevault.

 

[Mike Boreham]

So for the Mini M4, we don't need to disable the ability to boot from external disks and can go ahead to boot from an external drive?

Correct for all Silicon macs.

 

[Alameda]

Maybe if you don't have something constructive to say, don't say anything?

Well, OneDrive is hardly the only cloud storage provider in the world, so if their solution doesn’t work for you, find a different one?

 

[hajime]

.

 

[djbern]

I just got an M4 mini because, well, why not! I went with the 512GB option so there's a decent amount of space, but being the person I am I tend to hoard data and so added a 4TB external SSD.

Rather than boot off the external though - I'm keeping the OS and apps running off the internal drive and have followed one of the many YT tutorials on how to move just the Home folder to an external drive (OWC 1M2 with a Samsung 990 EVO Plus drive). It's working great so far and I haven't noticed any performance issues. Plus Apple Intelligence works just fine.

The only downside is that I can't encrypt the external SSD - the encryption for external SSDs is in keychain which doesn't load until the account loads. I could do it by booting into an account on the internal drive then switching to my main account, but that gets silly. This isn't a big deal because the machine is always going to be in my house vs. a laptop that I move around with.

I'm dumping tons of stuff into that account so we will see how it holds/performs over time...

do you have a link for the specific YT video you watched! Thanks in advance