This is exactly what the smartphone sector needs, as Samsung knows from personal experience—after being criticized for not including a microSD card slot in its Galaxy S6 series, Samsung built one into its recently introduced Galaxy S7. It's a popular feature for power users who find it all-too-easy to fill up their phone's built-in storage.
That's harder to do with 256GB, which offers four times as much storage as a 64GB smartphone. On top of the additional storage, Samsung says its 256GB embedded memory is nearly twice as fast as a SATA-based SSD. To put some hard numbers to that claim, Samsung rates its new memory as being capable of reading data at up to 850MB/s. Writes aren't as fast—up to 260MB/s—but still respectable, especially for a smartphone.
Samsung's memory is based on the latest revision of its Vertical NAND (V-NAND) flash memory. It can handle up to 45,000 and 40,000 input/output operations per second for random reading and writing, respectively, which is over two times faster than the 19,000 and 14,000 IOPS of the previous generation of UFS memory.
The way Samsung figures it, a next generation handset equipped with a USB 3.0 interface and its new memory would be able to transfer a 5GB-equivalent Full HD video clip (roughly 90 minutes long) in just 12 seconds. There would also be enough space to hold 47 Full HD movies. Not too shabby.