~20% PCIe SSD Slowdown in 10.13.5 vs 10.11

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,782
1,037
Pacific NW, USA
Running updated benchmarks for low level 4k performance, I've discovered an observable slow down in AHCI PCIe SSD performance. Old and new results are shared below... Perhaps the drop in performance is the result of patches for the Specter/Meltdown at the OS level. Unfortunately read and write speed is effected, no both drives tested.

10/2015 - ElCapitan - combined results
20151tbvs128.png



6/2018 XP941

xp941 slowdown.png

6/2018 Apple 1TB SSUAX
1tb ssd slowdown.png
 

eksu

macrumors 6502
Aug 3, 2017
268
124
Can you control more variables before we jump to conclusions? i.e. run the test on the same drives in 10.11 today

That way you can control for ssd degredation, control for Filesystem (unlabeled in 1st photo) control for how full the drive is, control for cpu microcode, control for other PCIe devices, etc?
 

bsbeamer

macrumors 68040
Sep 19, 2012
3,689
1,951
With APFS on non-Apple issued SSD, I was getting very slow read/write speeds back in 10.13.2 (one of the builds). Changed to HFS+ via Carbon Copy Cloner and all problems went away. I do not recommend APFS for 5,1 with non-Apple issued SSDs.
 
  • Like
Reactions: Synchro3

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,782
1,037
Pacific NW, USA
Cannot confirm a slowdown in 10.13.5 (However, I avoided the APFS format)

Apple SSUBX

View attachment 765260
Matching up with syncro3's and my legacy results, I forgot to click [x] Allow Asynchronous I/O.

Booting back into ElCap to verify, read performance on the xp941 looks good. Write performance consistently scales across multiple tests.
xp941 el cap.png

Back to High Sierra, read performance looks good but write performance is inconsistent. With the XP941 slowing down faster more times than not.

xp941 high sierra.png window6-8-1810.52 AM.png window6-8-1810.52 AM-1.png
 

Attachments

Last edited:
  • Like
Reactions: Synchro3
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.