Limited Edition 750GB Crucial MX300 SSD Review

By Nathan Kirsch

IOMeter Sequential Performance

Starting in April 2015 Legit Reviews brought back synthetic IOMeter v1.1.0 testing to our high-end Solid-State Drive reviews as we feel that the canned benchmarks no longer show enough of the performance picture nor do they expose many of the heat issues that we are starting to encounter on M.2 PCIe SSDs. We start out testing each drive with IOMeter, but first we prepare the drive. This is done by using Parted Magic to complete a full Secure Erase each and every drive. Next we use IOMeter to prefill the drive by performing the industry standard 128KB, aligned, sequential write workload across the entire drive for a period of 20 minutes. Once the drive is conditioned we run our saved sequential test profile that runs our 128KB test for one minute without any idle time in between the tests. The queue depth is set to 32 as we feel with NVMe drives starting to come out that we need to increase our IO depth.

mx300-128kb-mbps

The 128KB Sequential Read/Write test is done primarily to make sure the drives we are testing meet or surpass the manufacturer specifications for sequential Read/Write performance. The Crucial MX300 750GB SSD topped out at 533.7 MB/s read and 479.2 MB/s write. The write speeds are lower than one might expect on many of the drives as we do 1 minute sustained read/write tests and it fills the cache on the TLC drives.

mx300-128kb-iops

For those that like to know the IOPS results you are looking at around 4,100 IOPS for the sequential read and 3,800 IOPS on the sequential write.

mx300-128kb-ms

Having high IOPs per second is generally considered good, but you also look at the latency when interpreting the results. Just because the IOPs are high it might not mean that the data is being delivered at a reasonable latency and this could cause for a poor user experience. The Crucial MX300 750GB SSD did really well in this test beating all the other TLC based SSDs with the exception of the Samsung 850 EVO 500GB SSD.

mx300-queue-depth-testing

Here is a closer look at just the Crucial MX300 750GB SSDs sequential performance at various queue depths using short 10 second transfer tests tests. As you can see low QD levels still offer great performance and the MX300 750GB SSD tops out at its advertised read speeds at QD4 and the advertised write speeds at QD2. Very solid performance numbers!