Toshiba THNSNH256GCST and Performance Hit upon Reaching Half-Size Mark
You may remember that the OCZ Vertex 4 SSD suffered a performance hit when filled with data by more than 50%. The same effect can be observed with the Toshiba THNSNH series. The drive delivers high performance until it has more than 50% of free capacity, enjoying a leading position in real-life applications. However, as soon as it is filled with data by more than 50%, its performance goes down.
The OCZ Vertex 4 showed the same behavior in our earlier tests. It is based on the Indilinx Everest 2 controller, which is closely related to Marvell solutions. Using Marvell technologies as well, the Toshiba TC58NC5HA9CST controller seems to share something in common with the Vertex 4. So, here’s its behavior when it is filled with files by more than 50%:
The read speed remains the same but the write speed becomes too low for a modern SSD. However, this performance hit is not permanent. If the SSD is given some time to reorganize data in its flash memory, its speed returns back to normal with one exception. Here is the performance of the Toshiba SSD, half-filled with data, after a 15-minute idle period:
Every parameter is back to normal except for the speed of random writing with a long request queue, which is only half the original level. As opposed to the Toshiba, the OCZ Vertex 4 could fully recover its speed after being filled with data by more than 50%.
What does it mean in practical terms? The Toshiba is going to be slower when large amounts of data are being written incessantly on it. Moreover, the speed of certain applications that write data in multiple threads may also get lower, so the Toshiba THNSNH may not be as good as it seems after all.
We can show you the changes in its performance in benchmarks that simulate real-life loads:
The table shows that the SSD only slows down in certain scenarios that depend on the speed of writing to the SSD. The performance hit suffered by the Toshiba THNSNH doesn’t make it an unattractive product. In most situations it remains in the leading group together with the Plextor M5 Pro and OCZ Vector.