Best Way to Use External SSD as "Main" Drive

[macphoto861]

I'm setting up a new iMac soon. Internal storage is 256gb, and I'll be using a fast external 4tb Thunderbolt SSD with it as well, where most of my files will be stored. How I've handled this with my MacBook Pros is to let the internal drive be for OS, apps, and some files, while external drives store the bulk of my files. But in this case, I want the user folder to be on the external drive (so if I put something on the desktop, music folder, documents folder, etc., I want it to be stored on the external).

From what I've read, locating the user folder on a drive other than the startup drive is possible. If I did it this way, at least I'd be using the internal storage for something (OS and apps). Would it be better to do it that way, or to have OS/apps on the external, and the internal just sits there mostly unused?

 

[Rich B22]

I did the same setup on a 2017 Intel iMac putting the user account on an external connected to the USB port (not TB) and it worked fine. Eventually replaced the internal fusion drive with 2 x 1 TB SSD's and it's even better. The primary drive has the apps and OS, while the second drive has my user folder.

I may be wrong, but it's my understanding that with the M series Macs, you need the OS on the internal drive, otherwise it won't boot, even though you also have the OS on the external, therefore, IMO, I would use the internal drive on your new iMac for Apps and OS and have the User Folder on the external as you did on the Macbook Pro. Additionally, if you want to boot from the external, I would imagine as new versions come out, you'd have to update both drives.

If you're really short of space and want to run the apps from the external drive, it can be done, but is not a straight-line process. You drag the existing apps from the internal to the external ( I suggest a folder named "My Applications" or similar to differentiate from the Applications folder)and most will run ok, although, I've had a few that won't run if you change their location. When installing an app, you can just drag the install icon to the external rather than the internal, but not all apps give the option on install. You would then need to create a shortcut or symbolic link to your new My Applications folder on your desktop or dock.

Good luck

 

[iMac2019]

Hi,
you should have multiple solutions, from the simplest to the most complex.
it largely depends on how sensitive you are to how recover your data without any loss if necessary, and how urgently you need to get your organization back up and running.
how valuable, important and private are your data?
Of course, the answers to these questions will determine the cost and complexity of the solution.

For a first approach, you can take a look at

How to move your Mac user folder to a separate drive from the boot drive

Learn how to move your entire user folder to a different location, completely separate from your main drive.

www.idownloadblog.com

 

[macphoto861]

I may be wrong, but it's my understanding that with the M series Macs, you need the OS on the internal drive, otherwise it won't boot, even though you also have the OS on the external, therefore, IMO, I would use the internal drive on your new iMac for Apps and OS and have the User Folder on the external as you did on the Macbook Pro. Additionally, if you want to boot from the external, I would imagine as new versions come out, you'd have to update both drives.

So you have to have an OS on the internal drive, even if you're not booting to it? Interesting. But I guess I'd probably want to go ahead and keep an OS on it regardless, just to give myself another readily accessible booting option if something happened to the external drive.

To clarify though, on my MBP I don't actually have the user folder on an external, it's still on the internal... I just keep various files on the externals.

 

[macphoto861]

Hi,
you should have multiple solutions, from the simplest to the most complex.
it largely depends on how sensitive you are to how recover your data without any loss if necessary, and how urgently you need to get your organization back up and running.
how valuable, important and private are your data?
Of course, the answers to these questions will determine the cost and complexity of the solution.

For a first approach, you can take a look at

How to move your Mac user folder to a separate drive from the boot drive

Learn how to move your entire user folder to a different location, completely separate from your main drive.

www.idownloadblog.com

Thanks... that looks like it would work well for me.

 

[Fishrrman]

Before you consider booting from an external drive, do a drive speed test on the new iMac's SSD.

You may be surprised at how fast it is, vis-a-vis an external.
In fact, if you buy "the next size larger" from the base model (that is, if the base is 256gb, get a 512gb instead), the larger drive will be 2x as fast as the base model.

Before Apple Silicon, there were sound reasons to boot some Macs from an external SSD.
But with the advent of the m-series CPUs, it's easier (and generally "just as fast") to boot them from the internal drive.

 

[macphoto861]

Before you consider booting from an external drive, do a drive speed test on the new iMac's SSD.

You may be surprised at how fast it is, vis-a-vis an external.
In fact, if you buy "the next size larger" from the base model (that is, if the base is 256gb, get a 512gb instead), the larger drive will be 2x as fast as the base model.

Before Apple Silicon, there were sound reasons to boot some Macs from an external SSD.
But with the advent of the m-series CPUs, it's easier (and generally "just as fast") to boot them from the internal drive.

Yes, on my MBP, the internal drive is significantly faster than my Thunderbolt external NVMe. But from what I understand, the 256gb M3 iMac's storage is only around 1500MB/s (the Thunderbolt NVMe I intend to use with it is in the neighborhood of 3000MB/s).

Still, I'd be fine using the "slow" 1500MB/s internal for booting and apps... my goal is to end up with the user folder on the external, just trying to figure out if it's best to split them up like that (OS on internal, user folder on external), or to also install the OS on the external.

 

[Fishrrman]

OP wrote:
"Yes, on my MBP, the internal drive is significantly faster than my Thunderbolt external NVMe. But from what I understand, the 256gb M3 iMac's storage is only around 1500MB/s (the Thunderbolt NVMe I intend to use with it is in the neighborhood of 3000MB/s)."

If you buy the entry level iMac with a 256gb SSD, YES, you will get "the slower drive".

BUT...

If you special order it with 512gb (or 1tb), the SSD will be TWICE AS FAST as the base model.

And... probably the equal (in speed) of most external SSDs you would get.

You're better off buying the larger internal SSD and booting that way.
Fewer problems in the long run, as well.

 

[macphoto861]

If you special order it with 512gb (or 1tb), the SSD will be TWICE AS FAST as the base model.

And... probably the equal (in speed) of most external SSDs you would get.

Speed isn't the primary consideration on this particular machine. I mean, it's important, but it's replacing an older iMac with a hard drive, so any SSD is going to feel lightning fast in comparison. But if I were to go strictly with an internal SSD, 512GB or 1TB would not be enough, I'd need at least 2TB (which is the biggest Apple offers), and I'm not keen on spending $800 more just to squeak by... would rather spend less than half that, and get the 4TB external that will be plenty fast and give me more breathing room.

And yes, I realize I could do a hybrid approach... a 512GB or 1TB internal for the better speed, and a 2TB or 4TB external to store other files, but for the person who is going to be using this computer, it's important that the user folder be on the large drive, and again, because blazing speed of the internal is not super important here, it would be a bit of a waste to spend $200 - $400 more just for that.

 

[Fishrrman]

Um.....

You don't have to have "everything" on one drive.
Or even, on one partition.

Boot from the internal SSD.
Keep your apps on it.
Keep your account on it.

Got LARGE libraries?
They can be on an external SSD.

Also... stuff that isn't accessed very often.
Like... videos.

For many years, I've partitioned my internal drive into 4 partitions:
- Boot (for OS, apps, accounts)
- Main (for my MANY small files, personal stuff)
- Media (for photos and some videos, etc.)
- Music
That means a minimum of 4 drive icons on the upper right of my desktop.
No problems, it HELPS to segregate stuff to specific areas.

But I also maintain separate DRIVES, with additional archives of music, movies, and old tv shows.

Why cram all this onto one drive?
I WANT my boot drive to be "lean, mean and clean"...

 

[macphoto861]

Boot from the internal SSD.
Keep your apps on it.
Keep your account on it.

Got LARGE libraries?
They can be on an external SSD.

Same here, you're preaching to the choir. OS and apps (as well as some files) on the internal SSD, but photos, videos, stuff that I don't need readily accessible, big files, etc. are organized on several externals.

But this computer is for a person who does not operate that way (believe me, I've tried)... just about everything goes on the desktop! I'm not going to try to fight that "put all that stuff on the external drive" battle again. Hence, I'd like for at least the user folder to be on the external. OS and apps can be on the internal (or I might put these on the external too).

 

[macphoto861]

After more research and thought, I think I'm going to follow your advice and NOT have the user folder on the external SSD. There are numerous tutorials on how to do it, and it seems pretty straightforward at least on the surface, but there are also a lot of reports of odd behavior with this kind of configuration in MacOS versions of the past several years.

For some people it seems to work fine, but for others there are more complex issues that spring up. There are threads with dozens of posts that offer insight into working around these things, and even though I wouldn't be thrilled with having to deal with these potential complications myself, I'd be ok with it. But I don't want the family member this computer is for to be subjected to these kinds of things.

I also was able to study how she's got her current machine set up. Everything is not on the desktop as I originally thought... a lot of stuff is, but a manageable amount. Most photos, videos, etc., are in folders within the Home folder (and even some on externals already), so it wouldn't be that big of a change in her routine for these things to be moved to the external SSD.

My intention was to configure the machine so that the big 4TB external SSD essentially had the appearance of being "the computer" (housing the Home folder, and especially the desktop), for the sake of making the transition as smooth as possible, but I'm now seeing the potential for trouble as outweighing that convenience.

 

[ignatius345]

Boot from the internal SSD.
Keep your apps on it.
Keep your account on it.

Got LARGE libraries?
They can be on an external SSD.

Been doing this for quite a while now and confirm it's a good way to go. I moved the libraries used by Photos, Music and TV onto an external SSD and it all works quite well.

One super super important note: buy another, bigger drive and use the software of your choice to back up everything on your internal and that external drive. The backup drive can be a slow HDD, doesn't really matter as it's going to be doing its thing in the background.