Migration Assistant from Intel Mac Mini to M2 Mac Mini with external boot drives

More details are required to give good advise.

What year model is your current Intel Mac mini..?

What external SSD are you using for the startup drive..?

How large is the storage space on the new M2 Mac mini..?

What is the total space used on the external startup drive..?

I'm asking these questions, because running from the M2 Mac mini's internal drive is like 5 to 10 times faster than running from an external SSD startup drive.

With that in mind, if the M2 Mac mini's does not have enough storage space for everything.

The best solution is to only Migrate your settings over from the old to the M2 Mac mini.

see > Transfer to a new Mac with Migration Assistant - Apple Support

Put your larger Photos, Music or Movie Libraries on an external storage drive.

Move your Photos library to save space on your Mac - Apple Support

Change where your music files are stored on Mac - Apple Support

Move your iMovie for Mac library - Apple Support

Then startup from the faster Mac mini's internal storage drive and access your Libraries on the external SSD drive.

This short video will help you sail through the process if you follow it exactly. . . . especially the bit about Physical Disks and Volumes.

Boot from External SSD/HDD

I wouldn't advise using Migration Assistant as it can move across a load of rubbish that can impair the working of your new Mac.

Download apps afresh and just copy manually what you need on an as and when required basis.

For all normal Mac usage the speed of the external is immaterial as the limiting factor is the CPU.

The only time a slower SSD shows up is when copying huge files.

If you perform any bench tests using the internal or a USB 3.0 external SSD you will get identical results.

More importantly, if you do any real world test such as rendering or exporting, you will also get identical times.

I have been using my base M2 booted from a cheap 1 TB SSD for over a year and it has been blazing through processing video from Final Cut Pro and DaVinci Resolve.

Take a look at this brief video. Not only was I using Final Cut Pro to do an intensive process, I was also videoing it using Screenflow.

Even with those 2 powerful apps (and a few others going in the background) just see how responsive the computer is booted from the "slow" external.

Using FCP to become invisible!

Sorry Ian, but I do not agree.

The Mac mini's internal SSD's are 4, 5, 6 times faster and that has a lot to do with overall crispness and performance.

The speed of an external 3.0 SSD is around 480 MB/s Write and 500 MB/s Read.

The speed of my 2018 Mac mini's internal is 1995 MB/s Write and 2397 MB/s Read.

The speed of the wife's M1 Mac mini's internal is 2579 MB/s Write and 2613 MB/s Read.

Not sure what the speed of an M2 Mac mini's internal is, but I'm sure that it is better the the M1.

Charles Pillow wrote:

The Intel Mac Mini is: 2018; 3.6GHz quad-core Intel Core i3

External SSD is Samsung T5 500GB

New M2 Mac Mini internal storage: 256GB

Current storage being used on external Samsung SSD is: 334GB

I have a new external Samsung T7 1TB drive

I would setup and Migrate my personal settings to the M2 Mac mini.

I would access the Photos, Music or Movie Libraries on the 500GB T5.

Then I would use the 1T T7 to backup both the M2 Mac mini and the T5.

I am quite aware that an external USB 3.0 SSD is only a quarter the speed of an internal and like you I feared that booting from it would create a huge performance hit.

So I tested it with an old SSD, fully prepared to junk the idea when it didn't work . . . but it did work!

I will admit there is a reduction in speed but it is in the order of 1% which I think most people would consider as virtually nothing.

The only area where the speed difference is noticeable is when copying massive files, which obviously will take 4 times longer but which is something most users rarely do.

Anyway, don't take my word for it, get a bootable SSD and try it for yourself.

I have booted plenty of older HDD Mac's from SSDs over the years and that works wonders.

I find no value in booting any of newer Mac's with SSDs from an external SSD.

Instead I clone external SSDs for backup and emergency booting.

My purpose was simply to protect the tiny SSD from premature wear and tear exacerbated by memory swapping from the 8 GB RAM. The fact that there was no noticeable reduction in performance was an almost unexpected bonus.

As the M4 now comes with 16 GB RAM there should be less memory swapping so the need to protect the 256 GB SSD will be reduced.

No your Libraries on the T5 will up-date when accessed and used by the newer macOS version.

The macOS on the T5 can also be updated, if you desired to keep and up date it.

It's not a matter of whether you agree or not.

Just do the practical tests and you will find the truth.