SSD Configuration Question for 2017 iMac.

NYMinute

macrumors newbie
Original poster
Nov 21, 2011
29
11
Hi.

I bought a 2017 iMac with a 500GB SSD on Black Friday. I also bought a 1TB Samsung T5 SSD for external storage. I just received both last night and I haven't open them yet. I am upgrading from a 2011 iMac with an HDD so this will be my first experience with SSDs and will be the first time I use a Mac with APFS. I don't plan to do a data transfer from the old iMac. I will back up the photo and music libraries from the old iMac to external HDD as a back up but I plan to set the new Mac as a clean new computer and use itunes match and icloud photo to get my music and pictures in it. I have a few questions that hopefully somebody can answer.

Because the computer was custom order from apple with an SSD will it be factory formatted with APFS or will it have HFS+ and I will have to convert it?

Do I have to format the external SSD and set it to APFS before using it on the iMac or is APFS just for internal drives (I heard is good practice to format the external SSD before using it on a Mac regardless of file system)?

Is it good practice to set the locations for the iTunes library and the photo library to the external SSD so I don't fill the internal SSD? If I do, do I have to do something before I open these apps for the first time so they don't default the libraries to internal storage, is it all done when I first open them or do I have to change it on the settings after it has already created a library?

Thanks in advance for any information and I would also appreciate any other tips on what to put on the internal drive and what to keep on the external.
 

iTurbo

macrumors 6502
Sep 9, 2008
311
372
I'm using a 500 GB Samsung T5 with my iMac (w/Mojave) and Drive Setup didn't let me format it with APFS. Not really sure why, but it works fine nonetheless. I was able to format it with Mac OS Extended (journaled) though. The Samsung T5 comes formatted ex fat.

When I upgraded to Mojave, it reformatted my original Fusion drive with APFS, so if your iMac comes with Mojave preinstalled it should be APFS already.
 

iTurbo

macrumors 6502
Sep 9, 2008
311
372
An external SSD can be left HFS+ but changed both of mine to APFS and they are more responsive.

How were you able to format with APFS? I wanted to do this with my T5 before I CCC'd it, but Disk Utility didn't list it as an option.
 

Fishrrman

macrumors Core
Feb 20, 2009
19,660
6,846
OP wrote:
"Because the computer was custom order from apple with an SSD will it be factory formatted with APFS or will it have HFS+ and I will have to convert it?"

It will almost certainly come with APFS. I would be very surprised if it didn't.

I would suggest that any external drives you use (HDD or SSD) be formatted to HFS+.

If you don't do this, the drives won't be "connectible" to older Macs still running HFS+.

My opinion only.
 
  • Like
Reactions: Kevbasscat

nambuccaheadsau

macrumors 68000
Oct 19, 2007
1,835
433
Nambucca Heads Australia
Connected the external SSDs, one USB3 and the other TB, used DU to erase them and format APFS and SuperDuper to do a fresh cloning of Mojave and both work beautifully and somewhat faster than HFS+. As I have no older Macs, other than an original LC running OS 7.0.1 for my Apple camera, no worries with HFS+.
 

mikehalloran

macrumors 68000
Oct 14, 2018
1,747
445
The Sillie Con Valley
I would suggest that any external drives you use (HDD or SSD) be formatted to HFS+.
Why?

used DU to erase them and format APFS and SuperDuper to do a fresh cloning of Mojave and both work beautifully
Why?

I'm asking because there are very good reasons not to do either.
[doublepost=1544039628][/doublepost]
don't plan to do a data transfer from the old iMac.
This works only if your other applications have Mojave compatible installers and you have no work files (documents etc.) to transfer over.

Many work files will not open on your new Mac if you just copy and past between machines. There is a workaround and that is to zip your files before moving them over. Unzipping grants you privileges to those files on the new machine.
 

Fishrrman

macrumors Core
Feb 20, 2009
19,660
6,846
Mike, you seem to be biased against CarbonCopyCloner and SuperDuper.
Why is that?
 

iTurbo

macrumors 6502
Sep 9, 2008
311
372
So Disk Utility should be able to format a Samsung T5 SSD with APFS?

Disk Utility only shows these options in a drop down menu when you click erase:
Mac OS Extended (Journaled)
Mac OS Extended (Case-Sensitive, Journaled)
MS-DOS (FAT)
ExFAT

This is with Mojave 10.14.1 and Disk Utility 18.0
Late 2012 27" iMac and the T5 is connected to the built-in USB 3.0 bus.
 

mikehalloran

macrumors 68000
Oct 14, 2018
1,747
445
The Sillie Con Valley
Mike, you seem to be biased against CarbonCopyCloner and SuperDuper.
Why is that?
Not at all. There are times when I use and recommend it.

But I asked first. Why are you guys making the recommendations that you are? (hint — I want to see if you guys know anything at all about APFS)
So Disk Utility should be able to format a Samsung T5 SSD with APFS?

Disk Utility only shows these options in a drop down menu when you click erase:
Mac OS Extended (Journaled)
Mac OS Extended (Case-Sensitive, Journaled)
MS-DOS (FAT)
ExFAT

This is with Mojave 10.14.1 and Disk Utility 18.0
Late 2012 27" iMac and the T5 is connected to the built-in USB 3.0 bus.
Short answer: APFS is weird.

You have to be in Disk Utility but you convert to APFS from the Edit Menu. You will not lose data.

Converting back to HFS+ is a major pain and does involve data loss. For that and many other reasons, I do not recommend partitioning a drive into APFS and HFS+ partitions—and if you do, do not install more than one OS onto the drive (you really, really Really do not want to do that).
 

iTurbo

macrumors 6502
Sep 9, 2008
311
372
Short answer: APFS is weird.

You have to be in Disk Utility but you convert to APFS from the Edit Menu. You will not lose data.

Converting back to HFS+ is a major pain and does involve data loss. For that and many other reasons, I do not recommend partitioning a drive into APFS and HFS+ partitions—and if you do, do not install more than one OS onto the drive (you really, really Really do not want to do that).

Ah, I see it now under the Edit menu, but it is grayed out while the T5 is highlighted in Disk Utility.
 

Fishrrman

macrumors Core
Feb 20, 2009
19,660
6,846
Mike H wrote:
"Converting back to HFS+ is a major pain and does involve data loss. For that and many other reasons, I do not recommend partitioning a drive into APFS and HFS+ partitions—and if you do, do not install more than one OS onto the drive (you really, really Really do not want to do that)."

I'd have to agree with you there in principle.

The reason I recommend HFS+ for -external- drives (to be used for data storage) is that if the user chooses APFS, those drives won't be readable on other Macs that are still running under HFS+ (although I believe that High Sierra, even under HFS+, can "see" APFS anyway).

An HFS+ external still behaves well under APFS.

Perhaps 4-5 years down the line -- when a greater share of the "Macs in service" are using APFS, APFS on an external will become "the way to go".

But right now, HFS+ might be a better choice -- at least for users who encounter HFS+ Macs on a regular basis.
 

Kevbasscat

macrumors 6502
Oct 10, 2016
255
176
Banning, CA 92220
OP wrote:
"Because the computer was custom order from apple with an SSD will it be factory formatted with APFS or will it have HFS+ and I will have to convert it?"

It will almost certainly come with APFS. I would be very surprised if it didn't.

I would suggest that any external drives you use (HDD or SSD) be formatted to HFS+.

If you don't do this, the drives won't be "connectible" to older Macs still running HFS+.

My opinion only.

I wouldn't bet the farm on it. They blacklisted my 9,1 iMac, because it could take Mojave, so I bought a mid 2017 27" iMac in Nov 2018. You would think it would come with Mojave, but it showed up with HS. I made an appointment with support, and after a good 4 & ½ hours, we finally had Mojave running. Every step was a pain in some way, very unlike other Os's. So you might do well to ask first.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.