The Western Digital Black PCIe SSD (512GB) Review

Mixed Random Read/Write Performance

The mixed random I/O benchmark starts with a pure read test and gradually increases the proportion of writes, finishing with pure writes. The queue depth is 3 for the entire test and each subtest lasts for 3 minutes, for a total test duration of 18 minutes. As with the pure random write test, this test is restricted to a 16GB span of the drive, which is empty save for the 16GB test file.

The WD Black's mixed random performance is better than most SATA SSDs and better than the Intel 600p, but both the Samsung 850 EVO and 850 PRO have a clear advantage over the WD Black.

The WD Black's power consumption is a bit high by PCIe standards, but not quite as high as the Plextor M8Pe which uses the same controller. Given the sub-par performance of the WD Black, its efficiency is bad: on par with the Intel 600p, less than half that of the Samsung 850 EVO or Crucial MX300, and far behind that of the Samsung 960 EVO.

WD Black PCIe 512GBCrucial MX300 525GBIntel SSD 600p 512GBIntel SSD 750 400GBOCZ RD400 512GB (M.2)PNY CS2211 480GBPatriot Hellfire M.2 480GBPlextor M8PeGN (M.2) 512GBSM2260 512GB 3D MLCSamsung 850 EVO 500GBSamsung 850 Pro 512GBSamsung 950 Pro 512GBSamsung 960 EVO 1TBSamsung 960 EVO 250GBSamsung 960 Pro 2TBWD Blue 1TB

The WD Black's performance is pretty flat over the course of the mixed random I/O test, save for the typical jump in the final phase as the workload shifts to pure random writes. The jump isn't high enough to bring the average up above the best SATA SSDs, and the WD Black doesn't show the gradual improvement over the course of the test that the MLC PCIe SSDs experience.

Mixed Sequential Read/Write Performance

The mixed sequential access test covers the entire span of the drive and uses a queue depth of one. It starts with a pure read test and gradually increases the proportion of writes, finishing with pure writes. Each subtest lasts for 3 minutes, for a total test duration of 18 minutes. The drive is filled before the test starts.

On the mixed sequential I/O test the WD Black performs like a good but not great SATA SSD, with a slight advantage over the WD Blue.

The WD Black's power consumption during this test is on the low side of normal for PCIe SSDs, but its efficiency still isn't remotely competitive with Samsung's 3D TLC.

WD Black PCIe 512GBCrucial MX300 525GBIntel SSD 600p 512GBIntel SSD 750 400GBOCZ RD400 512GB (M.2)PNY CS2211 480GBPatriot Hellfire M.2 480GBPlextor M8PeGN (M.2) 512GBSM2260 512GB 3D MLCSamsung 850 EVO 500GBSamsung 850 Pro 512GBSamsung 950 Pro 512GBSamsung 960 EVO 1TBSamsung 960 EVO 250GBSamsung 960 Pro 2TBWD Blue 1TB

The WD Black starts the test with performance near the limit for SATA, but it drops from there as writes are added to the mix. The performance recovers slightly in the final two phases of the test. Power consumption climbs steadily over the course of the test, while most drives manage to reduce power consumption slightly as their performance drops.