Random and Sequential Read/Write
We use CrystalDiskMark 3.0.1 benchmark to test the random- and sequential read and write speed. This benchmark is convenient to work with as it can measure the speed of an SSD with both incompressible random and fully compressible recurring data. This feature is important for testing SSDs based on SF-2281/2282 controller, which tries to compress the data before writing it into the flash-memory. So, there are two numbers in the diagrams below that reflect the maximum and minimum SSD speed. The real-life performance of an SSD is going to be in-between those two numbers depending on how effective the controller data compression is.
Note that the performance tests in this section refer to SSDs in their “Fresh Out-of-Box” state (FOB). No degradation could have taken place yet.
We’ve mentioned above that the capacity of 120/128 gigabytes isn’t optimal for SandForce-based SSDs. The numbers you can see in the diagram confirm our point. While 256GB SSDs with SF-2281 controller deliver average performance in comparison with their opponents, their 120/128GB cousins are much slower. The only scenario in which such SSDs can outperform Marvell- or Indilinx-based ones is when they process compressible data.
The Silicon Power Velox V60 and the Transcend SSD720 behave like typical SandForce-based products with synchronous flash. They differ somewhat from the Corsair Force GT, yet this difference is too small, even though their Toggle Mode NAND flash can ensure higher performance than ordinary synchronous flash from Intel or Micron. The best SandForce-based SSD here is Intel’s SSD 330, though. As with the SSD 520 model, Intel’s exclusive firmware does the trick.
We can also see no fundamental difference between the Transcend SSD720 and the other SandForce-based products. It looks like the turning off of RAISE technology doesn’t affect its performance much, at least when the SSD is in its out-of-box state.