Thanks to the performance we see with the Sandisk WD Blue SN5100, the market now has not just one great QLC SSD, but two great QLC SSDs. We were first impressed by Crucial's P310, but the Blue SN5100 has quietly come along to redefine what a QLC drive can do. The Blue SN5100 carries on with this tradition, but it’s also marking the full transition from TLC to QLC flash. Sandisk WD Blue SN5100: A Closer LookImage 1 of 2 (Image credit: Tom's Hardware) (Image credit: Tom's Hardware)The Blue SN5100 is single-sided with a single NAND flash chip, power management circuitry, and a DRAM-less controller. This completely changes with the Blue SN5100 as a follow-up to the Blue SN5000.