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:

The M550's performance in sequential reading with incompressible test was high enough (517.45 MB/s), almost matching the performance quoted by Crucial. The same applies for sequential writing, where the drive wrote the incompressible files at 477.27 MB/s (average). It is obvious that Micron and Marvell have made a great job with the firmware of the drive, offering a performance consistency with all kinds of data.

At the 4K random reading tests, the Crucial M550 512GB is positioned close to the top of the chart below, with an average reading speed of 27.77 MB/s.

The drive also did it well in the 4K random writing tests with 71.78 MB/s:

Multi-threaded requests for random reading of 4K incompressible files were not an issue for the M550 SSD - an improvement over the previous M500 model. A great performance for Crucial's new offering:

In the following graph you see how the M550 512GB drive reads and writes files, which have been partially of fully compressed. It is obvious that the both reading and writing speeds do not depend on level of file compression: