The SanDisk X400 1TB SSD 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 SanDisk X400 is in a three-way tie for first place for low queue depth sequential read speeds, with measurably better performance than any other TLC drive, even the Samsung 850 EVO.

The X400's power consumption is about average, but significantly better than the other two top performers. It's nowhere near the efficiency of the Crucial BX100, but for a TLC drive it's impressive.

SanDisk X400 1TBCrucial BX100 1TBCrucial BX200 960GBCrucial MX200 1TBOCZ Trion 100 960GBOCZ Trion 150 960GBOCZ Vector 180 960GBSamsung 850 EVO 1TBSamsung 850 Pro 1TBSanDisk Extreme Pro 960GB

The SanDisk X400 is one of only four drives that delivers over 500MB/s at QD1, and it's the least power-hungry of that club. At higher queue depths many other drives are able to reach the same SATA speed limit and some do it with less power consumption than the X400.

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 SanDisk X400 is the second test on which it is clearly slower than another planar TLC drive: the OCZ Trion 150. Both are much faster than the other two planar TLC drives in this bunch, but are slower than the MLC drives by a similarly large margin.

The X400 draws the least power of any drive on this test, so at least it's still very efficient for a TLC drive.

SanDisk X400 1TBCrucial BX100 1TBCrucial BX200 960GBCrucial MX200 1TBOCZ Trion 100 960GBOCZ Trion 150 960GBOCZ Vector 180 960GBSamsung 850 EVO 1TBSamsung 850 Pro 1TBSanDisk Extreme Pro 960GB

Sequential write performance and power consumption for the X400 are essentially constant across all queue depths, while the faster drives see at least some improvement from QD1 to QD2.