A few years ago, Intel and Micron announced what they considered to be groundbreaking memory technology, 3D XPoint. Intel had for some time been offering small Optane SSDs for caching with this new type of memory, but recently launched the first large 3D XPoint SSD: the Intel Optane DC P4800X. We tested it.
Since the rise of SSDs, they have been using flash memory, also called NAND. Compared to traditional hard disks, this memory has much lower access times, where most of the speed gain comes from. In terms of sequential speed, the nano-chips are not particularly fast by themselves, but because they are controlled in parallel, high speeds can still be achieved.
The move from SATA SSDs to NVMe mainly brought up the speeds in workloads with a high queue-depth. In normal English: If there is a long queue of commands waiting, they can be processed very quickly thanks to the faster interface. What still went almost as fast were the assignments with shorter queues. The controller will not be able to perform smart tricks and is limited by the speed of the NAND.
3D XPoint is supposed to finally change that - you can read more about the way it works on the next page. The Intel Optane DC P4800X is an enterprise-oriented drive and is available in two capacities (375 and 750GB). We've tested the PCI Express 3.0 x4 card, but it's also available as an U.2 drive in a 2.5" enclosure. Both are pricey: for this variant you pay over 3700 dollars, which is equivalent to over 5 dollars per GB. There will also be cheaper consumer variants, but the Optanes will not be really affordable for the time being.