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 M8V's TRIM and garbage collection functions, I first put the drive in a "dirty" state. I used Iometer to fill 80% of the drive and then ran a random write test for 30 minutes. This had little impact on the M8V's read speed. However, its average writing speed dropped to a mere 70.20 MB/s.
Plextor M8V - Dirty
To see how well the M8V could recover, I let the computer sit for about 30 minutes and then reran the test. The drive wasn't able to reach the factory fresh performance shown in our earlier tests. However, its average write speed climbed up to 321.10 MB/s.
Plextor M8V - After TRIM
Lastly, I used Parted Magic to perform a secure erase on the M8V. With the drive wiped clean, it had average read and write speeds of 524.54 MB/s and 435.42 MB/s, respectively.
Plextor M8V - Secure Erased
Final Thoughts:
Plextor's M8V SSD is a great choice for the consumer looking for an easy and affordable way to improve the performance of their existing desktop or notebook computer. This entry-level drive combines Silicon Motion's SM2258 controller with Toshiba's 64-layer BiCS3 3D TLC NAND flash to deliver good performance and innovative features at a price that won't break the bank. Thanks to Plextor's PlexNitro technology, the M8V performed relatively well throughout most of our tests. In our sequential read and write tests, the 256GB version of the drive was able to read at speeds as high as 563 MB/s and write at speeds in excess of 505 MB/s. It also did reasonably well in our random write tests, producing more than 63,000 IOPS at low queue depths.
While Plextor's PlexNitro technology works well under normal workloads, it does have its limitations. If you have a heavy workload, where a consecutive write operation exceeds the size of the SLC cache, the M8V's write speed drops to non-accelerated levels. This drop in performance wasn't nearly as large as what we saw with the S3C. However, the drive's cache is still quite small. With the 256GB version of the M8V I was able to write a little more than 4GB worth of data before it filled. Given, this won't be an issue for the consumer looking to speed up boot or application load times, but if you have heavier workloads, you may want to consider other options.
Fast read and write speeds aren't the only things the M8V has to offer. The drive is compatible with Plextor's Plextool software and supports their PlexTurbo smart cache technology. The M8V also works with the company's PlexVault and PlexCompressor software, which have traditionally been reserved for their higher end drives. That being said, the M8V does not support Device Sleep (DEVSLP) or hardware based encryption. This probably isn't an issue if you're looking for an SSD for your desktop computer. However, these are things you may want to keep in mind if the M8V is going in a laptop or if data security is a concern.
According to Plextor, the M8V will be available some time in March in 128GB, 256GB and 512GB capacities. The suggested retail prices are expected to range from about $66 up to $149 with the 256GB version reviewed here going for about $90.
Highs:
- Available in 128GB, 256GB and 512GB capacities
- Silicon Motion SM2258 controller
- Equipped with Toshiba 64-layer BiCS3 3D TLC NAND
- Good sequential read and write speeds under most conditions
- PlexNitro technology optimizes performance without taking up SSD space
- Supports PlexTurbo, PlexVault and PlexCompressor technologies
- Large DRAM cache
- 3 year warranty
- Affordably priced
Lows:
- Not available in higher capacities
- Write speed drops when SLC cache is full
- SLC cache is small
- Does not support DEVSLP
- Does not support hardware based encryption
