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bear100

macrumors newbie
Original poster
Jan 9, 2023
29
2
as some of you very helpful chaps know I had issues with my old iMac and lost the use of the USB's and data transfer
today I have taken delivery of a new old stock 27" iMac for an awesome price!

I have a 512gb storage on the machine but want to use my new Samsung T7 2TB SSD as the storage to boot from etc not being the pc expert I will need some instructions if you could be so kind :)
 
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rm5

macrumors 68020
Mar 4, 2022
2,385
2,730
United States
Hey! It's pretty easy to get your installation running on an external drive! Mind if I ask what model you're running though? If it's an older one, it won't be natively compatible with the latest macOS version.
  1. Go here and download a macOS version you want. Once it's done downloading, launch the installer.
  2. When asked what volume you want to install it on, select your T7. You'll need to format the T7 as APFS first using Disk Utility if you haven't already done so.
  3. When the installation completes, you'll be booting off the T7!
 
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Fishrrman

macrumors Penryn
Feb 20, 2009
28,596
12,713
"I have a 512gb storage on the machine but want to use my new Samsung T7 2TB SSD as the storage to boot from"

It would help if you told us WHAT YEAR the iMac is.
Is it new enough to have USBc ports on the back?
That would make it either 2017, 2019, or 2020.

With that said...
If you have a relatively newer iMac with USBc, and IF it has a factory-installed SSD inside, IT DOES NOT MAKE SENSE to boot it from an external drive, even from an external SSD.

REASON WHY:
The internal SSD is [probably] much faster than will be an external USB3.1 gen2 SSD (which has read speeds around 910MBps).

What you need to do to get more information:
Download the FREE "Blackmagic Disk Speed Test" utility from the App Store.
Use it to test the speed of the internal SSD.
Measure this against the speed I gave you above for an external USB3.1 gen2 SSD.

There was a time (back in the days of platter-based internal drives) that it made sense to boot and run the Mac from an external SSD. I was a big advocate of doing things that way in this forum for years.
In fact, I did it myself for SIX YEARS with my 2012 Mini.
But with the advent of fast internal SSDs on Macs, that no longer is "the best way".

If you need more than 512gb storage, by all means buy an external SSD.
But keep booting/running from the internal.
It will probably be much "snappier" that way.
 
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bear100

macrumors newbie
Original poster
Jan 9, 2023
29
2
"I have a 512gb storage on the machine but want to use my new Samsung T7 2TB SSD as the storage to boot from"

It would help if you told us WHAT YEAR the iMac is.
Is it new enough to have USBc ports on the back?
That would make it either 2017, 2019, or 2020.

With that said...
If you have a relatively newer iMac with USBc, and IF it has a factory-installed SSD inside, IT DOES NOT MAKE SENSE to boot it from an external drive, even from an external SSD.

REASON WHY:
The internal SSD is [probably] much faster than will be an external USB3.1 gen2 SSD (which has read speeds around 910MBps).

What you need to do to get more information:
Download the FREE "Blackmagic Disk Speed Test" utility from the App Store.
Use it to test the speed of the internal SSD.
Measure this against the speed I gave you above for an external USB3.1 gen2 SSD.

There was a time (back in the days of platter-based internal drives) that it made sense to boot and run the Mac from an external SSD. I was a big advocate of doing things that way in this forum for years.
In fact, I did it myself for SIX YEARS with my 2012 Mini.
But with the advent of fast internal SSDs on Macs, that no longer is "the best way".

If you need more than 512gb storage, by all means buy an external SSD.
But keep booting/running from the internal.
It will probably be much "snappier" that way.
Thanks again Fishrrman, checked the speeds as mentioned and the internal drive is running over 2000MBps so its a winner.

so is there a particular way to set ups the T7 and use it as extra storage?
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,596
12,713
"is there a particular way to set ups the T7 and use it as extra storage?"

If it's going to be used for "data only" (NOT a backup drive using time machine, CarbonCopyCloner or SuperDuper), and if it's NOT going to have a copy of the OS on it, then I'd format it with disk utility to HFS+ ("Mac OS extended, journaling enabled, GUID partition format").

You -could- use APFS, but I prefer HFS+ for "data only" drives because 3rd party maintenance/repair utilities can still read HFS+.
They CAN'T be used with APFS.

You don't really need any Samsung-supplied software that may be on the drive.
Just erase with Disk Utility, and it should be ready to use.
 
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