TRIM Performance:
While SSDs 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 address 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 850 EVO mSATA's TRIM and garbage collection functions, 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 little impact on the 850 EVO mSATA's read speed. However, its average writing speed dropped to a mere 18.4 MB/s.
Samsung SSD 850 EVO mSATA - Dirty
To see how well the 850 EVO mSATA could recover, I let the computer sit for about 45 minutes and then reran the test. Looking at the screenshot below, you can see that the drive's average writing speed jumped up to 225.7 MB/s.
Samsung SSD 850 EVO mSATA - After Trim
Lastly, I used Samsung's SSD Magician software to perform a secure erase of the 850 EVO mSATA. With the drive wiped clean, it had average read and write speeds of 406.4 MB/s and 226.0 MB/s, respectively.
Samsung SSD 850 EVO mSATA - Secure Erase
Final Thoughts:
The mSATA version of the Samsung's popular 850 EVO SSD is finally here and, like the original, it delivers a lot of bang for your buck. Designed and built entirely in-house, the 850 EVO mSATA is based on Samsung's MEX/MGX controller and is available with up to 1TB of the company's 3-bit 3D V-NAND flash. The drive is also equipped with Samsung's innovative TurboWrite technology which uses a high speed buffer to maximize a user's everyday computing experience. Like its full size counterpart, the 850 EVO mSATA performed relatively well throughout most of our tests. In our sequential read and write tests, the 120GB version of the drive was able to read at speeds as high as 552 MB/s and write at speeds in excess of 476 MB/s. It also had no problems holding its own when doing random reads, but lagged behind other drives in our random write tests, producing a little more than 42,000 IOPS at low queue depths.
Samsung's TurboWrite technology does have its limitations. It does a great job of maximizing performance under normal workloads, but, once a consecutive write operation exceeds the size of TurboWrite's buffer, the 850 EVO mSATA's write speed drops to non-accelerated levels. If you use your computer primarily for web browsing, email or to play the occasional game, it's unlikely that you will ever run into this situation. However, if you have a heavier workload and are doing something like video editing, which writes large amounts of data, you may want to consider other options.
Of course, fast read and write speeds aren't the only things the 850 EVO mSATA has to offer. Along with support for technologies like RAPID and TurboWrite, the drive features AES 256-bit full disk encryption and is compatible with both the TCG Opal and IEEE 1667 specifications. The 850 EVO mSATA also supports the SATA Device Sleep (DEVSLP) standard which extends the battery life of a device by reducing the drive's power consumption when it's not in use.
The Samsung 850 EVO mSATA is available now in 120GB, 250GB, 500GB and 1TB capacities. Prices on Amazon.com start at $80 for the 120GB version and go up to $450 for the top of the line 1TB drive.
Highs:
- Small mSATA form factor
- Equipped with 3-bit 3D V-NAND
- Available in 120GB, 250GB, 500GB and 1TB capacities
- Features RAPID mode and TurboWrite technology
- Excellent sequential read and write speeds under most conditions
- Good random read and write performance
- Performs equally well with compressible and incompressible data
- SATA 6Gb/s interface
- Large SDRAM cache
- Supports TRIM, garbage collection and wear leveling
- AES 256-bit full disk encryption
- TCG Opal and IEEE 1667 compliant
- Works with SSD Magician software
- Reasonably priced
- 3 year warranty
Lows:
- Write speed drops when TurboWrite buffer is full
- RAPID mode is Windows only
