The ADATA XPG SX900 is no different than other drives in that the amount of physical NAND on board 128GB (1 GB equals 1 billion bytes) differs from what shows in Windows as the virtual measure is actually shown in Gib (1 GiB equals 1,073,741,824 bytes) even though Windows does not label it that way. 119GiB is what is available after the conversion and overprovisioning which is used to set aside unmolested NAND to maintain drive performance and integrity.
While on the topic of spare area and performance, there has been some buzz recently around TRIM performance and SandForce firmware 5.0.2a which the SX900 is currently running (and the latest available from ADATA). Basically, it doesn’t appear TRIM is working properly on this firmware version and we did some validation testing. We filled the drive and then performed a bunch of benchmark testing to dirty up the remaining capacity along with the spare area. Predictably, performance dropped dramatically. After triggering the TRIM command, benchmarks were run again and performance did not recover as it should. So, this confirms the issue with TRIM on this firmware. A secure erase did reset performance nicely proving there’s not some other issue at play.
What does this mean? For most users, not a whole lot. Unless you have
used the drive long enough or mostly filled the drive, it shouldn’t
manifest itself. However, the longer this goes on, the more likely a
slow down will occur as the blocks continue to dirty and erase cycles need to precede write cycles. Supposedly, the
next iteration of firmware from SandForce fixes this issue but it’s
unknown whether this will be a destructive update and when exactly it
will be available (we suspect, very soon). To be clear, this is a
SandForce firmware issue so potentially impacts all SandForce SF-2281
drives depending on the firmware they are using. At the very least in the meantime, users can back up their
drive, secure erase it and re-image it to restore performance although
this is a bit of a pain. Again, we aren’t picking on ADATA, this affects a number of manufacturers whom may or may not have been aware of the issue.
In the opening of the article, we made reference to ADATA’s marketing of the SX900 as the “most powerful SSD on Earth” and after spending some time banging on the drive do we feel that description is warranted? Nope. It’s really more or less equal to a fair number of drives on the market already. That’s not to say that it’s weak by any means. It certainly performed well on the tests and met the maximum specifications of 550MB/s reads and 520MB/s writes. Other than the matter of the firmware TRIM issue, which we can’t pin on ADATA, we have no complaints about the drive at all. There’s just not much to make stand out in the glut of SF-2281 drives on the market. For the $99 current asking price for the 128GB version, you are looking at about $0.83 per usable GB which is a decent price for a drive we would consider to be on the enthusiast end of the scale. This also includes the Acronis True Image HD software and the 2.5″ to 3.5′ adapter plate which sweetens the deal. For those with thoughts of an SSD purchase, the extras, the price, and the three-year warranty will need to be weighed with the competition for the best buying decision.
Legit Bottom Line: The ADATA XPG SX900 is another in a sea of SF-2281 drives that gives solid performance at an affordable price point. Owners and potential buyers of this and similar drives running firmware 5.0.2a should be watchful for the updated firmware that will correct the TRIM issue.