SSDs slowing down over time?

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Level 1

4 points

SSDs slowing down over time?

Hi all!

My iMac have been running slow for a year now becoming almost unusable, and what my surprise that when I run a speed test of my three year old 480GB OWC Mercury Electra 3G SSD drive I get a write speed of 86 MB/SEC and a read speed of 198 MB/SEC (way below it´s speed)

It seems it is normal for the SSD drives to slow down, but what amazes me is the fact that in two years they became slower than a regular HDD.

Have any of you experienced such a fast speed decrease on your SSDs?

:-)

OBS,iMac (27-inch Late 2009), Mac OS X (10.7.5), SSD in place of the optical drive

Posted on Dec 9, 2017 1:07 PM

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Answer 1

Best reply

samtenor

Level 4

1,684 points

Dec 11, 2017 6:37 AM in response to rafael_

Hi:

I can see you did your homework about using software to acquire the read/write speed in your SSD.

There might be some contributed issues in terms of SSD degrading over time.

1. TRIM often can extend the SSD life and since 10.10.4, Mac OS finally allowed TRIM to be supported for third party SSD. Check with vendors or users' feedbacks to see any issue with trimforce. Again, back up your system before attempting the steps below.

2. The SSD of yours, might be bad, rather than OWC's usual quality SSD - in hope, you might be able to contact OWC for RMA (check with warranty coverage).

Although 2009 iMacs use SATA - II (3 gigabit), you should be able to get a decent speed than what you are experiencing now.

Good luck

Sam

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Answer 2

Kappy

Level 10

361,741 points

Dec 11, 2017 6:37 AM in response to rafael_

First, those speeds are better than any HDD. Disk speeds usually are in Mbits/s which is MBytes/s multiplied by 8. Second, you have a 3G, not a 6G, SSD which is running on a 3G SATA bus on your computer. A 3G SSD has a maximum theoretical interface speed of 3Gbits/s or 250Mbytes/s. This is an interface rate, not a more typical data r/w rate.

How full is the SSD? All disks slow down as they are filled especially if you have not activated TRIM for it. Is it possible that your problem has little to do with the SSD or you have an SSD without TRIM enabled that is full of garbage that needs to be cleared?

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Answer 3

rafael_ Author

Level 1

4 points

Dec 11, 2017 6:35 AM in response to rafael_

Hi!

Thanks for your imput!!

I bought a new SSD, I get now 256 MB/SEC and a read speed of 269 MB/SEC, my computer is like new :-D

I will enable trim and follow other recommendations I have found and hope this SSD (Samsung) last more than two years :-)

Any way it looks like Planned obsolescence and here I go again buying other SSD!

Take care!

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