My desktop currently has a 120GB M500 Crucial SSD installed for booting my OS and related applications. It's not exactly a top-of-the-line drive by any means but it's more than enough for every day use. The spec sheet for this model claims I should be getting up to 500 MB/second reads and 400MB/s writes. So when I saw the results of my CrystalDiskMark test I was underwhelmed to say the least. It's worth nothing that this drive was 75% full at the time of the test so I understand this has the potential to affect speeds - But not this much!
56MB/s sequential writes?? Time to figure out what's going on here..
Troubleshooting steps
First off I needed to ensure that AHCI was enabled. AHCI stand for Advance Host Controller Interface. This is a hardware mechanism that allows software to communicate with Serial ATA (SATA) devices such as SSDs. Windows supports AHCI out-of-the-box by default but just to be sure I went into device manager to confirm the AHCI controller was enabled and running.
So it's enabled - Great! Now I just need to confirm that the SSD is being managed by this controller. Right click the controller, choose properties, then navigate to the 'Details' tab. In this section you are greeted with a drop down menu where I chose 'Children' and could see my SSD listed so AHCI is definitely enabled.
Then I needed to confirm that 'TRIM' was enabled. TRIM support is essential for an SSD to run the way it should to avoid slow writing times. This command allows an operating system to inform a solid-state drive (SSD) which blocks of data are no longer considered in use and can be wiped internally. To test if this is enabled you can run the command "fsutil behavior query DisableDeleteNotify". If this returns as 0 then TRIM is enabled.
The next step was to make sure I was at the latest revision of the firmware. The firmware download for my SSD comes as an ISO package so I stuck it onto a USB using unetbootin and made a backup of my current SSD before proceeding - I've had enough bad experiences to warrant backups! Thankfully the installation completed successfully without any issues and I was upgraded from MU03 to the MU05 revision. Rebooted and went through another benchmark with CrystalDiskMark. No improvement whatsoever.
So considering there was little to no change in the speeds I figured I would confirm the results with another benchmark tool - Atto disk benchmark. Now I'm seeing more along the lines of the expected speeds! At my maximum I reached over 500MB/s reads and maxed out about 140MB/s writes. I'm still a little disappointed with the write speeds though but this is a start at least.
As this was an SSD I was recommended to test out 'AS SSD Benchmark' which also confirmed that AHCI was enabled and my alignment was okay. This reported speeds were pretty much along the same lines as what I've seen so far with write speeds being reported between 113MB/s and 134MB/s. Still disappointing.
I went ahead and asked someone else to run the same test on their Crucial M4, which is an older model than mine. He was clocking double my write speeds with similar read speeds using the same test config as me. Only other difference between his test and mine was that his drive has higher total capacity with about 50% free whereas I only had 25% free. I went about reducing the space consumed on my drive and then re-ran the test only to receive roughly the same numbers again..
The conclusion
After a bit more digging I realised this was down to false advertising rather than anything being wrong with my drive / configuration. The M500 series drives are capable of up to 400MB/s write speed at the higher capacity spectrum of drives. My specific model - CT120M500SSD1 - I found is only capable of about 130MB/s which more or less matches up with the speeds I was recording in some of the benchmarks. Here is a screenshot from the product page on newegg:
