CrystalDiskMark — transfer rates
First, we'll tackle sequential performance with CrystalDiskMark. This test runs on partitioned drives with the benchmark's default 1GB transfer size and randomized data.
We've color-coded the results to make the 850 EVOs easier to spot. We've also highlighted the other Samsung SSDs, coloring the TLC and MLC drives in different shades.
Both 850 EVOs are near the front of the pack in our CrystalDiskMark tests. Even the 250GB unit delivers strong write performance, which is really no surprise. The 1GB test should fit easily inside the TurboWrite buffer.
HD Tune — random access times
Next, we'll turn our attention to random access times. We used HD Tune to measure access times across multiple transfer sizes. SSDs have near-instantaneous seek times, so it's hard to graph the results on the same scale as mechanical drives. The WD Black and Seagate SSHD will sit out this round to focus our attention on the SSDs.
The 1MB random write test trips up some of the SSDs, but not the 850 EVOs, which are competitive throughout. To be fair, virtually all the SSDs have comparable access times in the other tests. Tiny fractions of a millisecond separate most of the drives in most of these tests.