Does MacOS care about drive partitions?

[MacCheetah3]

The only "test" I was really wondering about was the Finder lag when opening windows or the open/save windows in applications. Which causes less lag: a large capacity mechanical drive with multiple partitions formatted HFS+ or an APFS formatted one with the same number of multiple volumes?

File transfer speed wasn't a problem for me…slow is slow no matter which format.

For me it makes no difference as I don't constantly run any mechanical drives anymore. I still have some mechanical HDs I use for backup but they're not turned on for regular use.

My guess is negligible.

Even with a USB NVMe, I can have a few second delay before the Finder will load the full file list and icons/previews. However, that seems to only happen the first time the drive is accessed following a fresh connection or computer boot/restart. Otherwise, at least from what I recall, the file directory/structure stays cached.

 

[bzgnyc2]

That’s fine. Nonetheless, I’ll elaborate a bit more to perhaps bring a little more clarity to my own reasoning.

• macOS Catalina pushed — some would use the word “forced” — boot drives to use APFS.
• Big Sur brought APFS to Time Machine drives. And if I recall correctly, it also automatically converted err (re)formatted newly chosen drives (e.g., if they were formatted HFS+) as APFS. It was certainly part of the APFS-HFS+ debate as most people were/are still using HDD for backups and APFS started out very rough, including but not limited to critical problems on Fusion Drives. Therefore, many wanted to maintain using HFS+ for TM, but Apple seemingly decided it was okay by the time Big Sur dropped.
I never paid close attention though, I assume, Big Sur is also when Disk Images went APFS. I can tell you with certainty DMGs are now default APFS.
• As noted in a different thread, Disk Utility — at least in the GUI — no longer provides the option for encrypted HFS+ formatting. I also point out Disk Utility stumbles — well, I said “grumpy” — when handling HFS+ Encrypted drives/volumes.
• Performance… Well.. Actually, the stars align...


Someone did an APFS vs. HFS+ test using that very method.

Should you continue using HFS+?

Which is faster with a hard disk: using APFS or sticking with HFS+? Are there any differences in their performance on SSDs?

eclecticlight.co

A snippet:

Good points and I think we're all looking at the same elephant just from different perspectives. Certainly HFS+ isn't going to last forever. If I had to guess a timeline, I'd say:
-2030: macOS goes read-only on HFS+
-2035: macOS drops HFS+ from the kernel -- perhaps retaining some non-kernel tools for reading/converting old .dmg
-2040: HFS+ turns into a pumpkin -- it doesn't support date/times past 2040

That would also be +/- consistent with the 35 year lifespan of HFS.


Then stepping back I am assuming someone using HDD today either a) has unique needs or b) just had them and they still work. Anyone buying a new storage device in 2025 should be buying an SSD unless they have unique needs. As someone who still has a few HDD and likes them, the vast majority of people should buy SSD unless they know they have a very specific need that is better handled by an HDD.

In that context, if someone has old HDD already formatted HFS+, I would say just keep it as such until it gets replaced (almost certainly with an SSD). I'm guessing that will happen before Apple drops HFS+ from macOS. If someone is buying a new HDD in 2025 because they have a particular need, let's dive into that need but guessing it will be better served by HFS+ for the next few years.

Last just want to clarify the issue with APFS on HDD is not sustained transfer rate / sequential I/O but rather its tendency to fragment (and also tendancy not to cluster certain directory information together). This won't be noticeable with fresh filesystems but rather will be an issue over time as files are written/rewritten/deleted/etc. Then a fragmented filesystem hurts HDD a lot more than APFS. As the author of that article noted:

As a disk fills with files and their data, their performance is expected to fall faster when using APFS. When used for more static storage, this may not result in significant degradation.