The Western Digital Black PCIe SSD (512GB) Review

Sequential Read Performance

The sequential read test requests 128kB blocks and tests queue depths ranging from 1 to 32. The queue depth is doubled every three minutes, for a total test duration of 18 minutes. The test spans the entire drive, and the drive is filled before the test begins. The primary score we report is an average of performances at queue depths 1, 2 and 4, as client usage typically consists mostly of low queue depth operations.

The sequential read speed of the WD Black beats the Silicon Motion SM2260 drives (both MLC and TLC), but the WD Black is otherwise way behind the rest of the PCIe SSDs.

The WD Black has lower power draw than any other PCIe SSD during the sequential read test, and its efficiency is better than almost all other TLC drives (SATA or PCIe). However, the WD Black's efficiency is still about 60% worse than 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

At QD 1 the WD Black is performing close to the limit of SATA, and it saturates by QD4 at almost 1.3GB/s. Power consumption never quite reaches 4W, so thermal throttling is very unlikely.

Sequential Write Performance

The sequential write test writes 128kB blocks and tests queue depths ranging from 1 to 32. The queue depth is doubled every three minutes, for a total test duration of 18 minutes. The test spans the entire drive, and the drive is filled before the test begins. The primary score we report is an average of performances at queue depths 1, 2 and 4, as client usage typically consists mostly of low queue depth operations.

The sequential write speed of the WD Black is tied with the WD Blue and outperforms only the drives using IMFT 3D TLC. The Samsung 960 EVO and all of the MLC SSDs in this comparison sustain much better sequential write performance.

The WD Black's power consumption during the sequential write test is on par with other PCIe SSDs, giving it a typical efficiency for planar TLC SSDs. The WD Black is more efficient than the Intel 600p but loses quite badly to the other 3D TLC drives.

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 hits steady state during the first phase of the test and power and performance remain the same for the rest of the test, except that power consumption jumps up a bit at the very end. At no point during this test does the WD Black's sequential write speed exceed what SATA SSDs are capable of.