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Speed problems with Samsung SSD 850 Pro

stigc56

Senior Member
Hi
I have a Blackmagic SSD Dock with 4 SSD Harddrives connected to my Mac Pro 6.1. 3 of the SSD's runs around 350mb/s write & read, but the 4th - a Samsung SSD 850 Pro - runs only 69mb/s write and 380 mb/s read. It's not that old and used rather seldom.
Any idea's what to do about the pretty low write speed? DiskSpeedTest Samsung SSD 850 Pro.png
 
I have tested the drive in another configuration, same result. Now I have formatted it and still same result. It's gone. Buying a new one.
 
I have tested the drive in another configuration, same result. Now I have formatted it and still same result. It's gone. Buying a new one.

Did you already activate the TRIM functionality?

If you are on a Mac, open the terminal and enter:

sudo trimforce enable

Make sure to check this page before ordering your new ssd;)
 
Both of my Samsung SSDs run very slow. About 400 mb/s. My Crucial MX500 gets 600 mb/s.

Maybe it's just a coincidence, but I'm done with Samsung. I just bought another Crucial but haven't installed it yet.
 
Just curios if any of you with slow drives have then mostly filled? Same rules apply to SSD as mechanical about leaving space... the fuller they get the more performance declines. Also higher chance of shortening its lifespan
 
I had the same problem with the same drive back in 2014. It turned out this generation was faulty and Samsung acknowledged the issue. As I remember it they released a software fix that only ran on Windows. My rig was a hackintosh so I managed to get a refund. I’m now a happy camper going with Crucial.
 
Just curios if any of you with slow drives have then mostly filled? Same rules apply to SSD as mechanical about leaving space... the fuller they get the more performance declines. Also higher chance of shortening its lifespan
I keep my drives about 20% empty. No more than 800 GB on a 1 TB drive. How much space do you think should be left?

I had the same problem with the same drive back in 2014. It turned out this generation was faulty and Samsung acknowledged the issue. As I remember it they released a software fix that only ran on Windows. My rig was a hackintosh so I managed to get a refund. I’m now a happy camper going with Crucial.
My problem is with two different generations of Samsung EVOs. Both of them had the same loss of speed. I'll see how it goes over time with my drives from other companies.

But I do think it's true that SSDs don't last forever. Performance can decline and they can fail.
 
Maybe something wrong with your SATA driver?
I had a speed problem once where my AHCI driver wasnt installed properly.
My system was using IDE instead.
 
Just curios if any of you with slow drives have then mostly filled? Same rules apply to SSD as mechanical about leaving space... the fuller they get the more performance declines. Also higher chance of shortening its lifespan

Mine are full and no issues. All 4.
I’m sure @EvilDragon mentioned this wasn’t an issue with ssd’s.
 
I’m pretty sure this is the problem you’re facing:


It seems Unix based systems don’t agree with the EVO series. Newly written files would read at proper speeds, but then gradually drop to lower than HDD rates over time. I had 2 of them, both with the same issue.

Good luck
 
I’m pretty sure this is the problem you’re facing:


It seems Unix based systems don’t agree with the EVO series. Newly written files would read at proper speeds, but then gradually drop to lower than HDD rates over time. I had 2 of them, both with the same issue.

Good luck

Disk Speed Test writes and new file to the drive to test. So I'm not sure this is the problem
 
Did you already activate the TRIM functionality?
I believe it's easier to use APSF instead which supports trimming from the start and is designed to handle SSDs.
The Samsung issue where the boot tiles are getting progressively slower, to the point now it’s pretty much like an HDD is an EVO 850 840 issue and not present with the 860 models.
 
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My test shows the Crucial slightly faster than the equal sized (2T) Samsung 850/860.
But what I paid the premium price for with the Samsungs is the warranty.
More of a security blanket.
If this Crucial has a long and happy life, I'll jump ship next time.
 
I bought a new. I have tried to repair the old one, enabling trim, trying to update firmware via a PC - bvadr - had to give up on windows, I couldn't even find a tool to format the drive!
It's gone. I asked one of the major companies here in Copenhagen and he said Samsung Evo 860 is what they use.
 
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