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ncrypt

macrumors 6502
Original poster
May 16, 2012
351
257
UK
I just ran a disk speed test on my Mid-2014 15" MBP and was surprised to see how low the write speeds are. Around a year ago, write was sitting at around 400MB/s and when new, around 700.

Is this normal / is anyone else experiencing this sort of performance degradation?
Screen Shot 2017-02-27 at 12.19.49.png
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
Not normal at all. Even after say a hundred TBs of writes, read/write speeds should be staying around 600-700 MB/s.

What operating system are you using?
Can you verify that TRIM is enabled? (it should be and would be strange if it were not)
What is your current disk utilization looking like?
Have you already ran Disk Utility First Aid?
Have you pulled SMART data to check the drive's health for any pre-failure warnings?
 

ncrypt

macrumors 6502
Original poster
May 16, 2012
351
257
UK
What operating system are you using?
Can you verify that TRIM is enabled? (it should be and would be strange if it were not)
What is your current disk utilization looking like?
Have you already ran Disk Utility First Aid?
Have you pulled SMART data to check the drive's health for any pre-failure warnings?

  • On the latest public release of Sierra: 10.12.3
  • Trim is indeed enabled
  • Around 45GB of free space
  • Disk Utility is reporting everything as healthy
Pretty stumped!
 

The Mercurian

macrumors 68020
Mar 17, 2012
2,153
2,440
OP I have the same era machine with 1TB SSD which has gotten hours of use everyday since new and I just ran a test with BlackMagic. Scoring >800MB/s for both read and write. Seems like something is not right with yours. FYI I have 160GB free. I have noticed if I let it fill up to less than about 80GB free space things slow down a bit. Maybe try freeing up some space ?
 

ncrypt

macrumors 6502
Original poster
May 16, 2012
351
257
UK
I have noticed if I let it fill up to less than about 80GB free space things slow down a bit. Maybe try freeing up some space ?

Hmm, mine is only a 256GB drive. After making some room, I now have 53GB of free space, which means over 20% of it is free

I restarted my machine, re-ran the test and my write speed now settles at around 249MB/s for a 2GB file test, and around 180MB/s for anything bigger.

I can't really make more room, but it's odd that it should require so much free space. It also seems odd that write speeds start so high, but then start to come down pretty quick.

speedtest.gif
 

The Mercurian

macrumors 68020
Mar 17, 2012
2,153
2,440
Hmm, mine is only a 256GB drive. After making some room, I now have 53GB of free space, which means over 20% of it is free

I restarted my machine, re-ran the test and my write speed now settles at around 249MB/s for a 2GB file test, and around 180MB/s for anything bigger.

I can't really make more room, but it's odd that it should require so much free space. It also seems odd that write speeds start so high, but then start to come down pretty quick.

View attachment 690415

Ah well don't directly compare to mine than as the 1TB is faster due to having more bus channels (or something). About space - yeah I also find it odd that mine requires so much free space. But then again, I do run alot of RAM hungry stuff and can easily and often do max the 16GB on my machine - so perhaps that translates into needing more swap space on the disk. I have not tested mine rigorously to figure out exactly how much free disk space I need - I just know it is more than one would expect! If I notice things getting consistently sluggish I free up space and that usually works.
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
Have you tried using Onyx Automation or an OS reinstall yet? Does the AJA System Test pull drive health statistics?
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,035
15,412
California
Try holding command-s at boot to start in single user mode. Then enter "fsck -fy" (without the quotes) at the command prompt. That should TRIM the drive and maybe speed things up. Just type reboot after to restart.
 
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ncrypt

macrumors 6502
Original poster
May 16, 2012
351
257
UK
Try holding command-s at boot to start in single user mode. Then enter "fsck -fy" (without the quotes) at the command prompt. That should TRIM the drive and maybe speed things up. Just type reboot after to restart.

Thanks Weaselboy, just gave that a shot, but still getting the same speeds
 
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