The Crucial MX300 750GB SSD Review: Micron's 3D NAND Arrives

Performance Consistency

Our performance consistency test explores the extent to which a drive can reliably sustain performance during a long-duration random write test. Specifications for consumer drives typically list peak performance numbers only attainable in ideal conditions. The performance in a worst-case scenario can be drastically different as over the course of a long test drives can run out of spare area, have to start performing garbage collection, and sometimes even reach power or thermal limits.

In addition to an overall decline in performance, a long test can show patterns in how performance varies on shorter timescales. Some drives will exhibit very little variance in performance from second to second, while others will show massive drops in performance during each garbage collection cycle but otherwise maintain good performance, and others show constantly wide variance. If a drive periodically slows to hard drive levels of performance, it may feel slow to use even if its overall average performance is very high.

To maximally stress the drive's controller and force it to perform garbage collection and wear leveling, this test conducts 4kB random writes with a queue depth of 32. The drive is filled before the start of the test, and the test duration is one hour. Any spare area will be exhausted early in the test and by the end of the hour even the largest drives with the most overprovisioning will have reached a steady state. We use the last 400 seconds of the test to score the drive both on steady-state average writes per second and on its performance divided by the standard deviation.

The MX300's steady state random write performance is below the MX200 but stays slightly ahead of the 850 EVO and well ahead of any planar TLC drive.

The MX300 earns a consistency score that is below the MX200 but about average, and certainly high enough for ordinary consumer workloads.

Default	Crucial MX300 750GBADATA Premier SP550 480GBCrucial MX200 1TBCrucial MX200 500GBOCZ Trion 150 480GBOCZ Trion 150 960GBPNY CS1311 480GBPNY CS2211 480GBSamsung 850 EVO 1TBSamsung 850 EVO 500GBSamsung 850 Pro 1TBSamsung 850 Pro 512GBSanDisk Extreme Pro 480GBSanDisk Extreme Pro 960GBSanDisk X400 1TBCorsair Neutron XT 480GBCrucial BX100 500GBCrucial MX100 512GBOCZ Trion 100 240GBOCZ Trion 100 480GBOCZ Trion 100 960GBOCZ Vector 180 480GBOCZ Vector 180 960GBIntel SSD 750 1.2TB (PCIe 3.0 x4 - NVMe)Samsung SM951 512GB (PCIe 3.0 x4 - AHCI)Samsung XP941 512GB (PCIe 2.0 x4 - AHCI)
25% Over-Provisioning	Crucial MX300 750GBADATA Premier SP550 480GBCrucial MX200 1TBCrucial MX200 500GBOCZ Trion 150 480GBOCZ Trion 150 960GBPNY CS1311 480GBPNY CS2211 480GBSamsung 850 EVO 1TBSamsung 850 EVO 500GBSamsung 850 Pro 1TBSamsung 850 Pro 512GBSanDisk Extreme Pro 480GBSanDisk Extreme Pro 960GBSanDisk X400 1TBCorsair Neutron XT 480GBCrucial BX100 500GBCrucial MX100 512GBOCZ Trion 100 960GBOCZ Vector 180 480GBSanDisk Ultra II 240GB

The MX300 lasts for over eight minutes before the SLC cache and spare area are completely exhausted, but during that phase it alternates between operating at about 22k IOPS and 65-70k IOPS. During the steady state phase there is gradual improvement in performance along with an increase in variability.

Default	Crucial MX300 750GBADATA Premier SP550 480GBCrucial MX200 1TBCrucial MX200 500GBOCZ Trion 150 480GBOCZ Trion 150 960GBPNY CS1311 480GBPNY CS2211 480GBSamsung 850 EVO 1TBSamsung 850 EVO 500GBSamsung 850 Pro 1TBSamsung 850 Pro 512GBSanDisk Extreme Pro 480GBSanDisk Extreme Pro 960GBSanDisk X400 1TBCorsair Neutron XT 480GBCrucial BX100 500GBCrucial MX100 512GBOCZ Trion 100 240GBOCZ Trion 100 480GBOCZ Trion 100 960GBOCZ Vector 180 480GBOCZ Vector 180 960GBIntel SSD 750 1.2TB (PCIe 3.0 x4 - NVMe)Samsung SM951 512GB (PCIe 3.0 x4 - AHCI)Samsung XP941 512GB (PCIe 2.0 x4 - AHCI)
25% Over-Provisioning	Crucial MX300 750GBADATA Premier SP550 480GBCrucial MX200 1TBCrucial MX200 500GBOCZ Trion 150 480GBOCZ Trion 150 960GBPNY CS1311 480GBPNY CS2211 480GBSamsung 850 EVO 1TBSamsung 850 EVO 500GBSamsung 850 Pro 1TBSamsung 850 Pro 512GBSanDisk Extreme Pro 480GBSanDisk Extreme Pro 960GBSanDisk X400 1TBCorsair Neutron XT 480GBCrucial BX100 500GBCrucial MX100 512GBOCZ Trion 100 960GBOCZ Vector 180 480GBSanDisk Ultra II 240GB

The steady state random write performance of the MX300 varies periodically between about 6k IOPS to 10k IOPS, with no outliers of slow performance. With extra overprovisioning performance is substantially higher and consistency is a bit better.