We move on with the AS SSD benchmark, which contains five synthetic as well as three practical tests. The synthetic tests determine the sequential and the random read / write performance of an SSD. These tests are carried out without using the operating system's cache. The Seq-test measures how long it takes to read and write an 1GB file. Most importantly, this sequential benchmark uses incompressible data for all of its transfers.

The 4K benchmark tests the read and write performance for random 4K blocks. The 4K-64-THRD-test corresponds to the 4K procedure except that here the read and write operations are distributed on 64 threads:

TheDD512'ss performance in sequential reading with incompressible test was nevertheless the same we previously saw - at 322 MB/s for read and 193 MB/s for write.

Again, the rest of the results prove that the drive has not been optimized to access or write small files fast enough, at least compared with other SSDs.

At the 4K random reading tests, the Samsung SSD reached the top of the chart below, with an average reading speed of 33.03 MB/s.

The drive was slower at the 4K random writing tests, giving 68.8MB/s:

In the following graph you see how the Lexar DD512 drive reads and writes files, which have been partially of fully compressed. It is obvious that the both reading and writing speeds are pretty stable and do not depend on level of file compression.