macOS APFS File Format Speed

Currently I am running my internal Crucial SSD and one USB 3.0 External SSD with the new APFS file format. I have read many articles online about whether or not there is a speed increase using the APFS file format for macOS. It seemed like my Late 2012 iMac was a little snappier, but I decided to do some tests to confirm.

Speed Tests

I have a neat little App on my iMac called Diskmark from inchwest Software. I have a previous article on Macessence describing how Diskmark functions. Here is how the Diskmark people describe their app:

Benchmark the performance of your flash (pen/usb), solid state, hard disk drives in just 60 seconds. DiskMark performs real world speed tests and shows:

  1. Sequential read/write speeds which is the performance you see when copying large files.
  2. Random read/write speeds which is the performance you experience when opening or using programs that read and write a lot of files to disk.

I ran Diskmark on my internal Crucial SSD and external USB 3.0 SSD. Here is the results from the internal SSD:

Now, my previous speeds using HFS+ formatting on the Internal Crucial SSD were usually about 350 Read and 430 Write. The 400/496 speed of the APFS format is quite an improvement over my previous HFS+ formatting.

There was a similar speed increase on my external USB 3.0 drive running a Crucial SSD. Here is the Diskmark test:

Typically, I would see speeds of 330/375 on this external drive running the HFS+ file format. The 395/405 AFPS format speed is quite an improvement for sure.

I know people are having some issues with the new APFS file format. I am sure Apple will fix whatever needs to be fixed in future macOS High Sierra updates. But, there is no mistaking the benefits of the APFS format either. As previously mentioned, I did gain several gigabytes of space on my internal Crucial SSD when it was formatted to APFS. Along with the speed increase, which is noticeable, I do not regret updating my drives to High Sierra and APFS. YMMV, you just have to measure the benefits with the detractions to see if it is worth it for you to upgrade at this time.


I am glad I updated to the APFS file format. There are definite benefits for me. However, APFS will not work for everyone at this time. Eventually, we will all have to be there, but I am sure the APFS file format will be more stable and mature by then with fewer bugs.