Considering NVMe M.2 boot for 2014 iMac 5k, Have Questions

[nfable]

Hi -
in my iMac 15,1 I have USB 3.0 and ThunderBolt 2. I am considering an external enclosure connecting via TB as a boot option if I will see appreciable performance gains.

I have a 1TB Fusion drive going on now.

Looking for connecting 2 NVMe's. A double enclosure would be choice. One NVMe for boot / core storage, the other as a scratch disk and present work edit drive (video).

My Q's:
- Any recommendations on enclosure? A straight TB2 would be ideal, but they are EOL and possibly eBay-able. Other option is a TB3 with Apple TB3 -> TB2 Adapter.

- Will this be noticeably faster than the Fusion drive I currently use? (128GB Blade SD0128F + 1TB ST1000DM003)

- Recommendations on NVMe M.2 that will support MacOS boot with no issues over the TB connection.

- Will potential bottlenecks I am unaware of make this scenario stupid?

Much thx,
nf

 

[mj_]

If I were you I wouldn't even bother with TB2 drives and simply go with a large USB 3.0 drive, such as Samsung's T5 or T7, instead. Yes, an NVMe drive connected via TB2 will be faster on paper but a) it will cost you an arm and a leg, and b) you won't notice the difference. Both of them will be leaps and bounds faster than the HDD part of your Fusion Drive.

Which brings me to a third possibility: why not split the Fusion Drive and use the 128GB SSD portion as boot and application drive? You could either swap out the internal hard drive for a large SATA III SSD or add one externally via USB.

 

[nfable]

Thanks mj - I suppose I could have my home folder on external and OS / Apps solely on the blade. I guess I am getting in the weeds looking for 'the max' transfer rates.

I don't upgrade oftern and am takng a deep dive at the possibilities. I don't have much experience with the newer M.2 in real world performance TB2 vs say an internal SSD over internal SATA connection if I swap the 7200 from the Fusion set.

Now I'm thinking, split the Fusion - replace the 128gb Apple Blade with OWC Aura 2tb. Partition the OWC tb with 200gb for OS/Apps, 800gb scratch, 1tb for primary edit bay of video, then either keep the 7200 hdd (old Barracuda) or replace with WD Gold for user folders. Not exactly cheap or easy - but cleaner, perhaps
?

 

[mj_]

Never have your home folder on an external drive. While it is technically not violating UNIX conventions it's a bad idea nonetheless.

Other than that go for it. The major performance benefit of SSDs is not necessarily their sequential read/write speeds but their much much lower latencies when accessing random data. We're talking orders of magnitude here. That's why you will see a huge improvement when going from HDD to SATA-III SSD but only minor improvements going from SATA-III SSD to NVMe SSD.

 

[nfable]

Thanks for that, main reason for wanting home folder on another drive is the size of my documents / pictures / movies really. Is there a better way to do that: meaning have the necessary (Apps / OS) and the recommended home folder things on the blade while having the space hungry storage elsewhere?

 

[mj_]

What's stopping you from saving all your stuff elsewhere? The folders inside your home folder aren't anything magical or unique, they're just that: folders. The only special folder is your Library. Everything else can be moved elsewhere.

 

[nfable]

My lack of imagination apparently. 🙃 Thanks for helping me think differently - guess I'm not thinking enough about the right things!

 

[Fishrrman]

"Thanks for that, main reason for wanting home folder on another drive is the size of my documents / pictures / movies really."

You can re-locate your "large libraries" on external drives WITHOUT moving your home folder from the internal boot drive.

For an example I will use Photos (but it could be the library from any photo app):
Just copy the existing "Photos library" file from your home folder to another drive.
It can be in another folder if you wish (probably a good idea). Give the folder a recognizable name.
Then, launch Photos WHILE HOLDING DOWN THE OPTION KEY.
Photos will ask you to choose the library you wish to use.
Select the one on the external drive.
Photos will remember that in the future.
You can now delete the [old] Photos library in your home folder.
That's really all there is to it.

Should work with music apps as well (iTunes or Music).
For movies/videos, apps like iMovie, Final Cut, etc., should behave the same way.
For downloaded movies -- put them anywhere you wish.

My own home folder (on this 2018 Mini) has almost nothing in it (what IS in it, is mostly in the "library").