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 V30'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. Looking at the screenshot below, you can see that the V30's average read and write speeds dropped to 115.4 MB/s and 172.1 MB/s, respectively.
Silicon Power V30 - Dirty
To see how well the V30 could recover, I let the computer sit for a few hours and then reran the test. The drive's average read speed climbed up to 266.0 MB/s. However, its write speed still lagged a bit behind, averaging out at 199.8 MB/s.
Silicon Power V30 - After Trim
Lastly, I used OCZ's Toolbox utility (yes, it works) to perform a secure erase on the V30. With the drive wiped clean, its write speed jumped back up to 332.6 MB/s.
Silicon Power V30 - Secure Erase
Final Thoughts:
The Velox Series V30 is the first SSD from Silicon Power to come through the 'Labs. Like many of the drives on the market today, it's based on SandForce's popular SF-2281 controller and comes equipped with a 6Gb/s SATA interface. Early reviews showed that the V30 was capable of delivering performance on par with high-end drives from companies like Kingston, OCZ and Patriot, but with the drive Silicon Power sent us, this really wasn't the case. Under ideal conditions, the V30 was able to read at speeds as high as 544 MB/s and write at speeds in excess of 460 MB/s. However, due to its use of asynchronous NAND, these numbers dropped considerably when working with incompressible data. On a more positive note, the drive supports TRIM and garbage collection technology and comes with a three year warranty as well as a 3.5" adapter bracket.
Performance aside, the biggest issue I have with the V30 is the switch from synchronous to asynchronous NAND. When asked about this, Silicon Power stated that, depending on market price, they may use NAND from different manufacturers. This isn't unheard of, but the switch to cheaper, asynchronous NAND is something that the consumer needs to be made aware of. Currently, there is no way to tell what type you're getting without opening the drive up (and voiding your warranty) or by running a few benchmarks and trying to figure it out that way. Instead, what Silicon Power really needs to do is sell these asynchronous equipped drives under a different SKU or model name and at a much lower price point.
The V30 is available now in 60GB, 120GB, 240GB and 480GB capacities. The 120GB reviewed here can be purchased from Amazon.com for about $225.
Highs:
- Available in 60GB, 120GB, 240GB and 480GB capacities
- Good sequential read and write speeds with compressible data
- SATA 6Gb/s interface
- Supports SMART, TRIM and garbage collection
- Equipped with DuraWrite and wear leveling
- Well constructed
- Includes a 2.5" to 3.5" adapter bracket
- 3 year warranty
Lows:
- No way to tell if you're getting a drive with asynchronous NAND
- Considerably slower with incompressible data
- Hard to find in some markets
- Pricey
