Using SSD USB as boot drive?

[Julien]

Just 'inherited' a late 2012 Mac mini and decided to replace my now obsolete 2008 Mac Pro. Had an unused SSD and have found using Blackmagic that it is FAR faster than the internal HD. So doing the following.

• USB SSD as boot drive
• Internal HD as nightly CCC clone of boot drive (easy revert)
• Time Machine backup of USB SSD boot drive

Is this a good strategy and are there any downsides to this?

Internal drive and USB SSD:

 

[keysofanxiety]

Well it's a 2012 model, so SSDs perform pretty well over USB 3. If it was 2011 or earlier I'd suggest against it.

Honestly, you shouldn't have any issues. Of course it won't be too healthy if it's unplugged randomly, and it won't be as fast than if fitted internally through SATA; but other than that, you needn't worry!

 

[Fishrrman]

OP:

Your "after" numbers above look good.
Be aware that about "the fastest" speed obtainable using USB3 is around 435mbps for "reads" -- so you're very close to the max.

Don't -- repeat, DON'T -- harbor any reservations about booting and running the Mini this way.

I've been booting and running my own late-2012 Mini since January 2013 this way, since I first took it out of the box.

I've had NO "downsides". It boots and runs fine.
Fast and smooth, NEVER crashes.

DISREGARD those naysayers who will warn you that "you can't enable TRIM" because you're using USB3.
In my personal experience over nearly four years, the lack of TRIM has made NO DISCERNIBLE DIFFERENCE in the performance of my SSD or Mac at all.

That means, NONE.

Enjoy the new speed!

Edit:
My Mini came with a 1tb 5400 HDD inside. I left it "in place".
However -- I partitioned the internal drive. The "first" partition is used to hold a CarbonCopyCloner cloned backup of the SSD. The other partitions are used for specific storage (to keep the SSD "lean and clean"), such as a partition for music, one for media (pics and videos), one for general storage, etc.

With the bootable cloned partition I -ALWAYS- have an immediately-accessible second boot source online and on my desktop if I require it.
NO Mac user should be without one.

 

[Julien]

...DISREGARD those naysayers who will warn you that "you can't enable TRIM" because you're using USB3.
In my personal experience over nearly four years, the lack of TRIM has made NO DISCERNIBLE DIFFERENCE in the performance of my SSD or Mac at all.

That means, NONE

.....With the bootable cloned partition I -ALWAYS- have an immediately-accessible second boot source online and on my desktop if I require it.
NO Mac user should be without one.

Thanks, even if lack of TRIM reduced my write performance by 50% it would still be significantly faster that the internal HD. So no real downside and read is far more important for day to day operations/speed.

Also as stated I'm cloning my SSD back to my internal HD nightly so I can Command-C and boot up just like 'normal' at any time.

 

[Julien]

Just one more question and I think I know the answer but....When I reboot my mini will it automatically boot from the USB (last used) drive and NOT revert back to the internal HD? So I DON'T have to Command-C every reboot.

 

[Fishrrman]

Go to Startup Disk in system preferences and set the external USB3 SSD to be your boot drive.

Nuthin' to it.

 

[Julien]

Go to Startup Disk in system preferences and set the external USB3 SSD to be your boot drive.

Nuthin' to it.

Already set and what I figured. Just wanted the easy answer (instead of having to reboot to see).

 

[jbarley]

Just one more question and I think I know the answer but....When I reboot my mini will it automatically boot from the USB (last used) drive and NOT revert back to the internal HD? So I DON'T have to Command-C every reboot.

I don't see "Command-C" in the list of OS X startup key commands.
What exactly does it do for you?

 

[Julien]

I don't see "Command-C" in the list of OS X startup key commands.
What exactly does it do for you?

Sorry, mistaken memory. I should have checked before posting. It is hold Alt/Option key. Haven't done it in a long time and just pulling it off the top of my head. Probably confusing with Command-R for some reason. Will forget again in about 5 minutes and if I need it will have to do a search anyway.

 

[jbarley]

Will forget again in about 5 minutes and if I need it will have to do a search anyway.

As an 80yr old I'm familiar with "forgetting".

 

[steve217]

OP:
Edit:
My Mini came with a 1tb 5400 HDD inside. I left it "in place".
However -- I partitioned the internal drive. The "first" partition is used to hold a CarbonCopyCloner cloned backup of the SSD. The other partitions are used for specific storage (to keep the SSD "lean and clean"), such as a partition for music, one for media (pics and videos), one for general storage, etc.

Your setup is intriguing, however, how would you enable encryption on the general-use storage volumes?

I have a fused internal 250GB SSD + 2 TB FileVault volume that I would like to dedicate for user storage and use an external SSD for boot.

How could I use the encrypted internal volume for home folders and boot from the external? MacOS balks when you try to put the home directory on separate encrypted folder.

 

[Fishrrman]

steve wrote:
"Your setup is intriguing, however, how would you enable encryption on the general-use storage volumes?"

I generally don't bother with encryption.
I'm more worried about encryption "going bad" on me -- and not being able to get at MY OWN data -- than I am about anyone else stealing it.
There's not much to see in my stuff, in any case.
Almost nothing "worth encrypting".
I choose to keep things "in plain sight".

Hmmm.... I -do- keep a USB flashdrive in the car, with CCC clones of my "boot" partition and my "main" partition.
I -did- encrypt the main partition, using FileVault. Seems like I remember doing this while running from the boot partition on that flashdrive.

I did this only because the car could get stolen. In that case, all the thieves would get is a flashdrive...

 

[nollimac]

Intrigued by your not installing the SSD in the Mini...any particular reason or just don't want?

 

[Fishrrman]

"Intrigued by your not installing the SSD in the Mini...any particular reason or just don't want?"

After reading post after post after post after post about folks who figured they could install a drive in the Mini, then opened it, and then…. BROKE SOMETHING inside -- not worth the risk to me.

Easier just to plug in a USB3 SSD.
Works just as well, almost as fast, no danger of accidently breaking something.

I did upgrade the RAM from 4 to 10gb by adding a single 8gb DIMM in "the top slot" (when opened).

 

[macdragonfl]

"Intrigued by your not installing the SSD in the Mini...any particular reason or just don't want?"

After reading post after post after post after post about folks who figured they could install a drive in the Mini, then opened it, and then…. BROKE SOMETHING inside -- not worth the risk to me.

Easier just to plug in a USB3 SSD.
Works just as well, almost as fast, no danger of accidently breaking something.

I did upgrade the RAM from 4 to 10gb by adding a single 8gb DIMM in "the top slot" (when opened).

I did the same as the OP when I first got my 2012 i7, which I bought 2 months before the 2014 came out. The reason was because of warranty. I use the Thunderbolt to run a 27" Asus QHD monitor at 2560 x 1440 res and was going to get a Thunderbolt hub to run both. Due to the high cost of Thunderbolt hubs and enclosures I just used a usb3 thought it would be a temporary solution until the price of the hubs came down. I do have 16 GB of memory. Over time I just found no need to do anything else as I partitioned the internal drive to mirror the SSD and the other partition to do time machine backups. I really could not be happier with my choice.

 

[Julien]

Just checked and I'm (still) getting up to 305MB write and 422MB read.