Samsung 840 Pro SSD Shows Slow Benchmark Speed

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Level 1

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Samsung 840 Pro SSD Shows Slow Benchmark Speed

Hi there..

Last week I bought a Samsung 840 PRO (512GB) SSD and cloned my existing HDD.

After successfully cloning my SSD and the booting was really quick and I was really excited. So I thought I'd run a Benchmark Test and started the Blackmagic Benchmark Test app. Found out the speed wasn't as fast as it was in from the SSD box. Was really disappointed by that.

The speed is supposed to be like this Read/Write: 540MBps/520MBps but mine was 266.5MBps/211.7MBps. Not sure why it is very very slow.

So I thought doing a Trim process will fix it and I did Enable Trim using Trim Enabler app. Still no luck.

Any suggestion, what is going on and how to fix this?

Oh btw I have a MBP 2010 15" Model.

Riaz

MacBook Pro, OS X Mavericks (10.9.1), MBP 15" (2010 Model)

Posted on Feb 25, 2014 8:34 PM

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Answer 1

Dibenkorn

Level 2

405 points

Feb 25, 2014 8:50 PM in response to Dematrix

Your MBP has a SATA II disk interface rated at 3 Gbps. That is a theoretical maximum of 375 MB/s. You are measuring 266/375 or about 70% of that maximum. That is a reasonable rate. If you had a SATA III connection running at 6 Gbps and you achieved the 540 MB/s you quoted, that would also be about 70% of the theoretical maximum.

If you stop looking at the bandwidth numbers, how does your Mac perform with its new SSD? Does it boot quickly? Do applications start quickly? If you have large-memory applications do the run faster now?

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Answer 2

Feb 25, 2014 8:59 PM in response to Dematrix

especially after running tests, you need to boot to an alternate System Drive, install and enable TRIM Enabler, and run Disk Utility (Repair Disk) against the SSD.

If all is working properly, you get a very satisfying additional line near the end of the test:

"Trimming Unused blocks"

... and it pauses for up to a minute while completing the process.

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Answer 3

Dematrix Author

Level 1

0 points

Feb 25, 2014 11:04 PM in response to Dibenkorn

Hi there...

Booting considerably faster than the original HDD. Tried opening few apps and seems faster response. Especially Firefox with alot of tabs opened. Dreamweaver seems to be bit faster than before.

Is there a way to change the SATA cable to SATA III?

Also it is advisable?

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Answer 4

Dibenkorn

Level 2

405 points

Feb 26, 2014 7:41 AM in response to Dematrix

When I put one in a SATA II capable Mac I was also pleased with the results. There is unforuntatly no way to upgrade the SATA II channnel to SATA III. It is built into the chipset.

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Answer 5

keg55

Level 6

11,743 points

Feb 26, 2014 7:46 AM in response to Dematrix

As Dibenkorn mentioned, you're getting the best you can get from your SSD since the chipset on your 2010 MBP is SATA II. The only way to get better would be to upgrade your 2010 MBP to the newer model which has the Intel chipset and SATA III. Then you would get 6Gbps with the SSD instead of 3Gbps.

I added a Crucial M500 into a 2008 MBP and got lower than expected bench marks for the same reason. The chipset is nVidia and SATA II (3Gbps). Just make sure your Linked Speed and Negotiated Linked Speed in System Information for the SATA bus are each 3Gbps.

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