Best SSD format to use, APFS or HFS+ with Lightroom Classic catalogue files

[cvdunton]

I am awaiting a new Mac Studio with an 8TB SSD to replace my late 2013 MacPro which I use almost exclusively for Lightroom Classic. Currently my Lightroom Classic catalogue files and backups are running on an external Raid5 volume made up of 4 240GB SSDs formated as HSF+. Once my Mac Studio arrives I will be done with external drives except for backup copies and TimeMachine. 

My plan is to divide the new 8TB SSD into a 1TB section for the OS and a 7TB section for all other files. That means my LR catalogue files will be running on an APFS formated SSD. Would LR run better if I created a separate 1TB section just for its cataloge files and formated that section as HFS+, leaving a 6TB section in APFS format for everything else?

Thanks

Charlie

[Ian Lyons]

APFS is the optimum format for SSD on Apple computers. See this Apple document for more details on APFS https://support.apple.com/en-gb/guide/disk-utility/dsku19ed921c/mac

Regarding partitions - I suggest you read this Apple document re APFS and how you can split your SSD https://support.apple.com/en-gb/guide/disk-utility/dskutl14027/mac

[Jao vdL]

>My plan is to divide the new 8TB SSD into a 1TB section for the OS and a 7TB section for all other files.

You do NOT want to do this. The hard drive is already separated into two partitions for the OS and your user files. You're far better off just using the default setup your Studio will come with. Especially since it is extremely easy to completely brick your computer (seriously lots of people have bricked their M1 Mac by reformatting the internal drive!) by repartitioning the startup disk. The OS partition is locked down as a security measure and files are only written on the user partition. The OS presents them to you as one contiguous hard drive but behind the scenes it is split up so it already has the functionaility you are looking for. This default arrangement also lets it dynamically rearrange the partitions. Manually repartitioning the drive runs the risk of deleting the hidden recovery partitions if you don't know very well what you are doing.

Always use APFS for any SSD from Mac OS X. HFS+ is only useful for oldfashioned spinning drives.

[Conrad C]

In addition, before you do any dividing of your internal Mac drive, make sure you fully understand the difference between partitions and APFS containers, and how volumes currently work in macOS 12 on an Apple Silicon Mac.

The traditional way to divide a storage device is to partition it, but partitions have always had some level of inflexibility, even as more recent versions of macOS made it easier to change partition sizes.

With today’s macOS, as much as possible you should avoid partitioning, and instead divide a storage device by creating APFS containers instead. They are more flexible about sharing storage space (with Reserve and Quota settings), and much easier to reconfigure without having to reformat the whole thing. Partition only if you have a really good technical reason for doing so, and never for the reason “I think it might improve…” You have to be sure. 

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@cvdunton wrote:

Would LR run better if I created a separate 1TB section just for its cataloge files and formated that section as HFS+, leaving a 6TB section in APFS format for everything else?

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It probably won’t make any noticeable difference to make it worth the trouble. Not when the Mac Studio internal SSD is capable of an amazing 5 to 7 GB/sec throughput, which is several times faster than the already blazing fast SSDs in recent Macs. That’s up to 14 times faster than a common SATA SSD, and almost 60 times faster than a good hard drive. Lightroom Classic just doesn’t do enough sustained storage access to bog down that fast of an SSD. Any Lightroom performance bottleneck is going to be somewhere else, like not being fully optimized for the GPU.

It also wouldn’t make sense to carve out an HFS+ partition for Lightroom Classic because then you’d throw out all of the SSD performance and optimization advantages of APFS, in favor of creaky old hard-disk oriented HFS+. Even more important, the APFS article I linked to above says:

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Note that in general it’s worth avoiding adding any partition or HFS+ volume to the internal storage you normally boot your Mac from. This is particularly true for Apple Silicon Macs: add an HFS+ partition/volume to their internal SSD and strange things can happen.

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@cvdunton wrote:

My plan is to divide the new 8TB SSD into a 1TB section for the OS and a 7TB section for all other files.

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You really don’t need to do that. Because macOS already does that, in the last few major versions of macOS, in a way that greatly enhances OS security. If you did it your own split on top of the non-optional split that macOS already does out of the box, you would complicate things for no good reason.

In macOS 10.15 or later, you are always operating within the user Data volume. The running system is actually a read-only snapshot of the Sealed System Volume (separate volume), which you (and malware) can’t modify.

It sounds like you would benefit from studying how macOS has changed in the last few years. These articles help explain the built-in, mandatory split containers separating system data and user data since macOS 10.15: 

Working with APFS Volume Groups

How macOS is more reliable, and doesn’t need reinstalling

Signed System Volume: added security protection

[cvdunton · Accepted solution]

Thanks to all of you for taking the time to reply with such extensive information and an excellent list of further reading material. What I thought was a simple question was born of more than 25 years experience with Mac HFS+ formatted HDDs and almost no experience with APFS. Having now read many of the articles you suggested I can say I have a better understanding of the many things I didn't know I didn't know and it is quite an long list.

My thought behind creating a second APFS container on the 8TB SSD was a result of the extensive backup program I have employed for the last 8 years with my trashcan MacPro. My MacPro has a boot SSD, but it is devoted strictly to holding the operating system, which at this poing is still Mojave. All of my data is stored on a 5TB HDD, except for the Lightroom catalogue files which, as I mentioned are on 4 SSDs in a RAID 5 configuration. Each night all three of these drives, Boot, Master Data, and Lightroom Catalogues, are automatically cloned to additional HDDs which are always mounted. In addition, I occasionally connect a third set of HDDs and clone my 3 main drives to them for storage offline. And since APFS was just a gleam in the eye when this system was set up, everything is still in HFS+ format.

This backup system has worked well for me for the last 8 years and has provided excellent protection for my catalogue of 120,00 images made over the last 20 years. But I can now see that going from a 256GB HFS+ boot SSD to a massive 8TB APFS SSD that will contain all of my precious data is going to require a significant rethinking of my processes, particularly my backup process. Who would have thought I would own a computer where system files and data files are closely connected by things like "bi-directional worm holes" to quote the good folks at Carbon Copy Cloner. 

But those questions are for a different thread. Thanks again for educating me so well and in such a cordial manner. 

Much appreciated,

Charlie