32 GiB write test

One of the main disadvantages of TLC Flash memories is its low write speed. Most SSDs that use this kind of memory compensates this by including in its controller chip a small amount of fast SLC Flash memory, acting as a write cache.  So, in these models, write operations with small amount of data are fast, because the data are stored in the SLC cache and later, when the drive is idle, the controller transfer them to the TLC memory chips. But when you write a big amount of data (more than the SLC cache), the speed drops significantly.

In order to benchmark it, we used CrystalDiskMark 5, on sequential write modes, with two repetitions and 32 GiB test file. Let’s check the results.

Samsung 960 PRO 512 GiB

On the sequential write and queue depth of 32, while the Samsung 960 PRO and the HyperX Predator keep the same speed of the 1 GiB test file benchmark, the Samsung 960 EVO was 61% slower than in the 1 GiB test.

Samsung 960 PRO 512 GiB

On the simple sequential write benchmark, again the Samsung 960 PRO 512 GiB and the HyperX Predator 480 GiB mantained the same performance, but the 960 EVO was 70% slower than on the 1 GiB test.