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MarinoMike

macrumors newbie
Original poster
Jul 19, 2017
3
0
So I just upgraded from an 120gb 840 EVO to a 256gb 850 Pro SSD in my 2011 MBP. This thing just seems a tad slower than 840 EVO when I was anticipating the opposite...slower in bootup and shutdown particularly.

The benchmark in Disk Sensei is giving some worrying latency figures...it's even slower than my EVO drive!

SATA 3 is working and TRIM is enabled so I'm not sure why this is happening...

Both drives were benchmarked within minutes of each other so it's definitely nothing to do with the SATA cable.


Is there any other Mac utility which allows drive latency testing?


850 PRO bench:
kbFPClU.png

840 EVO bench:

aNOkUNm.png
 

MarinoMike

macrumors newbie
Original poster
Jul 19, 2017
3
0
Does the 850 need a firmware update? Were the tests run with a fresh install of the os?

Thanks for replying.

850 Pro is running the latest firmware EXM04B6Q.

The tests were run on a fresh install but only after sufficient period of idling. There was no spotlight indexing going in the background or any other major I/O processes.
 

jerryk

macrumors 604
Nov 3, 2011
7,418
4,206
SF Bay Area
Could the drive still be busy rebuilding the indices used by spotlight and other utilities? Leave it running for a day and then retest.

Impressive improvement in throughput on the 850.
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
How long ago was the install done? How long ago was TRIM enabled? How was the install done - fresh OS install or clone?
 

MarinoMike

macrumors newbie
Original poster
Jul 19, 2017
3
0
How long ago was the install done? How long ago was TRIM enabled? How was the install done - fresh OS install or clone?


Install was done about 90 minutes before.

Enabled TRIM first thing on the fresh install.

No cloning. Fresh install using El Cap USB installer.

I ran tests again today and it's still giving about the same figures.

Tried manually TRIMing the drive and still no change in those latency numbers. :(
 

jerryk

macrumors 604
Nov 3, 2011
7,418
4,206
SF Bay Area
Install was done about 90 minutes before.

Enabled TRIM first thing on the fresh install.

No cloning. Fresh install using El Cap USB installer.

I ran tests again today and it's still giving about the same figures.

Tried manually TRIMing the drive and still no change in those latency numbers. :(

Since you are experiencing performance issues I would assume the issue is with the drive. If it were not for the performance issues I would think the program has an issue. I used a EVO 850 in a similar MacBook and it was very fast. But I never worry about latency with SSD since there is no rotation in the drive.

You might want to also change the drive connecting cable. These are known to start failing and lead to stalls and other issues.
 
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