Tuesday, September 26, 2017

APFS Benchmarks

Malc (via Hacker News):

As you can see, APFS’ encryption takes about 53% of file system 4K read speed, 32% of 4K write speed, 65% of 1M read speed and 47% of 1M write speed. That is a lot compared to HFS+’s accordingly: 41, 7, 4 and 0.1%.

Even without encryption, the results show HFS+ as faster.

Michael Larabel:

Some have complained of slowdowns with APFS, but for the most part my benchmark numbers are showing faster results.

Bombich Software:

These tests also demonstrate that boot time performance between HFS+ and APFS are comparable, with only one notable exception. The pre-encrypted APFS volume (both as a source and destination) encountered a very noticeable stall during startup when the progress indicator had filled to approximately 25%. I would not conclude that these numbers reflect a degradation of performance of the filesystem when it is pre-encrypted, rather it seems there is a flaw in the startup process that is specific to this filesystem variant. Regardless, if boot-time performance is important to your workflow, we recommend that you establish macOS on a non-encrypted volume initially, then enable FileVault via the Security & Privacy Preference Pane.

His test Mac was a 2011 Mac mini. Presumably a newer Mac would have less of a performance penalty for enabling encryption.

Update (2017-09-29): Mac:

in some cases APFS appears to be slightly slower than HFS+ when it comes to writing data, especially in smaller chunks

AFFS appears to be a lot faster than HFS+ when it comes to reading data

AFPS’ built-in encryption shows decreased throughput speeds in comparison to HFS+ with FileVault2

seek rates seem a tiny bit higher with APFS but that would be unnoticeable on most workflows

Update (2018-01-11): fG! (via Peter Steinberger):

We can observe that the performance loss between Sierra to High Sierra (HFS+ to APFS) is considerable and around 40% or more.


APFS appears to introduce a considerable performance loss, even against an HFS+ encrypted filesystem. I heard before some buzz about APFS performance issues but this was the first time I installed High Sierra outside a virtual machine and measured its performance.

5 Comments RSS · Twitter

Another thing where APFS appears to be slower is overall directory search and browsing. For my app "Find Any File", which now uses searchfs() in the current beta version, I've already gotten several reports from people who report a much longer search time on the disk than before, like, over a minute where it took only 10-20 seconds before. This may be due to the now-larger Catalog file (I'm still investigating this, though)

APFS is very much faster than HFS+ when you have 1000 or more files in a directory. HFS+ performance suffered greatly in this situation, whereas APFS maintains its performance regardless of the number of files - or at least I haven't discovered its limits yet.

First link has an updated version linked on top from 28 September
Second link is a comparison between Sierra with HFS and High Sierra with APFS

[…] Previously: Local Time Machine Uses APFS Snapshots, APFS Benchmarks. […]

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