TRIM Performance:
While SSD's offer many benefits, there are some downsides to using flash memory. One of the biggest issues people run into is performance degradation. Over time, an SSD will run out of fresh blocks and will have to write over data the file system has marked as deleted. This procedure is very complicated and can slow an SSD's write speeds considerably.
To fix this problem, most manufacturers have added TRIM support to their SSDs. The TRIM command allows an operating system, such as Windows 7, to tell an SSD which data blocks are no longer in use. Using this information, the drive pro-actively erases these blocks and adds them to the free block pool.
To test the Black²'s TRIM function, I first put the drive in a "dirty" state. I used Iometer to fill the entire drive and then ran a random write test for 30 minutes. This had very little effect on the Black²'s read speed. However, its average write speed dropped to 37.01 MB/s.
WD Black² SSD - Dirty
I let the computer sit for about 30 minutes and then reran the test. Looking at the screenshot below, you can see that the Black²'s average write speed had increased to 126.85 MB/s.
WD Black² SSD - After TRIM
Final Thoughts:
Pairing an SSD with a hard drive isn't exactly a new concept. For years, enthusiasts have been using SSDs to improve their boot and application load times while storing infrequently accessed files on inexpensive hard drives. With the Black², Western Digital has brought this concept to the mobile market. Instead of having to choose between an SSD or hard drive, this dual drive storage solution offers the best of both worlds by combining the two into a single unit. Powered by JMicron's JMF667H controller, the SSD portion of the Black² provides 120GB of NAND flash for your operating system, games and applications. While not one of the faster SSDs we've tested, it performed as expected in our tests, reading at speeds as high as 436 MB/s and writing at speeds in excess of 138 MB/s. The HDD portion wasn't nearly as fast but, with its 1TB capacity, it serves its purpose as a place to store personal data and large files. Western Digital also provides a generous 5 year warranty as well as some great documentation and videos on how to install the Black² and clone your old hard drive.
Aside from the Black²'s somewhat mediocre SSD performance, the only real complaint I have about the dual drive is its price. It currently retails for $289.99 at both Amazon and Newegg which is a pretty steep price considering you can get a mid-range 120GB SSD and a 1TB hard drive at nearly half the cost. Given, this won't get you the convenience of having a single drive but there are other alternatives out there like Samsung's 840 EVO SSD. The price of the 512GB EVO is very close to that of the Black² and, while offering half the capacity, will give your system an even bigger performance boost.
Highs:
- Dual drive with 120GB SSD and 1TB hard drive
- Single SATA 6Gb/s interface
- MLC NAND flash
- Good HDD performance
- Includes Acronis True Image cloning software
- Includes USB to SATA transfer cable
- Easy installation and setup
- 5 year warranty
Lows:
- Pricey
- Mediocre SSD performance
- Performance drops when SSD and hard drive are accessed at the same time
- Windows only
