Samsung 840 Evo 120GB SSD Underperformance

I got a SDD for my new PC and installed it as the boot drive, however I have been running some benchmarks and am confused on the results. For reference, this drive is listed to have 540 MBps Sustained Sequential Read and 410 MBps Sustained Sequential Write speed.

AS SSD Benchmark:



Crystal Disk Benchmark:


The performance seems a little slow on the read I am using a 6 GB/s SATA cable and have already tried using Samsung Magician to optimize the drive. Does anyone have any suggestions?

essenbe said:

Your motherboard most likely does not have sata III ports. You are running on sata II ports most likely. The cable used won't make any difference if the port itself is not sata III. That being said, those numbers are not bad at all. Try running the test on the mechanical drive it replaced.

I don't mean to be rude, but im not that dumb. My motherboard doesn't have any Sata II ports, only Sata III.

This is my motherboard:
ASUS M5A99X EVO R2.0 AM3+ AMD 990X + SB950 SATA 6Gb/s USB 3.0 ATX AMD Motherboard with UEFI BIOS - Newegg.com

I will run the benchmarks on the mechanical drive when I get home and post them back here.
Is it possible I just got an underperforming SSD? I'm honestly disappointed because the Samsung SSD's are more expensive than other brands and have better reviews. I could have paid $20 more and gotten double the capacity.

Thanks for responding btw, ive been having trouble recently getting any help on different forums.

essenbe said:

You're still getting decent numbers though. I'll save you the trouble. Here id a Western Digital Black 6 GB/s

Thanks. Looks like I do get a good performance jump over a mechanical drive. Should I not expect to be getting that close to the manufacturer listed read and write speeds for me SSD? This is normal?

essenbe said:

To some extent yes, and the numbers will change every time you run a test. But, don't run many tests on it. Running too many will slow it down for a while until it has a chance to 'clean' itself up. Actually, the 4KB read speeds and access times are the only numbers you will use on an OS 90% of the time. The rest are not really important unless you transfer 10GB files around.

Alright, thanks for the help!

Can't say im a little disappointed to know that other people with cheaper drives have faster access speeds though haha.

Well I'm glad you lot have got this far !

Firstly, the migration software fails. I've done a clone with another third party software. But, whenever I put the drive in, nothing happens and the laptop kind of turns itself of and then back on repeatedly.

F2 for setup doesn't work whilst it's doing this.

Does anyone think I've got a faulty SSD?

Thanks in advance

Those benchmarks are excellent , mine is far worse and i have a new 240 gb SSD.