A single NAND package as used in SSDs almost always contains multiple NAND dies (up to 16), commonly exposed through two or four independent channels per packag

A single NAND package as used in SSDs almost always contains multiple NAND dies (up to 16), commonly exposed through two or four independent channels per package (M.2 drives with 8-channel controllers frequently have just 2 NAND packages). A 256GByte NAND package must contain multiple NAND dies, because nobody makes 2Tbit NAND dies yet. Each NAND die is partitioned into two or four planes that can operate more or less independently, save for sharing the same uplink to the SSD controller. So while it is reasonable to worry about reduced parallelism in small SSDs when moving to newer, larger NAND dies, it is wildly incorrect to say that a 256GB drive has no capability for parallelization.