SSDs used to look a lot like HDDs but this is about to change, with the release of the "Ruler" form factor for Intel SSDs, a new solid state drive form factor enabling up to 1PB of storage in a 1U server rack in the future.

The new "ruler" form factor, so-called for its long, skinny shape, shifts storage from the legacy 2.5-inch and 3.5-inch form factors that follow traditional hard disk drives, and the add-in card form factor, which takes advantage of PCIe card slots, and delivers on the promise of non-volatile storage technologies to eliminate constraints on shape and size.

The majority of big cloud providers are using the U.2, and the rest are using the M.2. These form factors got the job done at the time, but they weren't optimized for newer types of non-volatile memory. For example, M.2 designs targeted light, thin notebooks. Cloud providers have embraced PCIe-based SSDs in a big way over the last couple years, in both the U.2 and M.2 form factors.

The new form factor delivers the most storage capacity for a server, with the lowest required cooling and power needs.
The next-generation "ruler" form factor SSDs using Intel 3D NAND technology will enable up to 1PB in a 1U server - enough storage for 300,000 HD movies, or about 70 years of nonstop entertainment. The SSDs will accommodate 3DNAND, Dual Port, or Optane technologies, each of which, on its own, dwarfs the performance of older storage technology. It can fit up to 48 media sites onto a single drive. This is a significant jump even compared to the now-current NGSFF form factor, which can fit 36. Both Intel Optane SSDs and Intel 3D NAND SSDs in the "ruler" form factor will come to market in the near future.

The "ruler" form factor is also supported by EDSFF, a group working to create an industry standard specification for this new SSD size, shape, capacity, and connector. EDSFF intends to publish the final specifications to allow for the new SSD form to become industry standard and replace the numerous existing forms for dense data center storage - drafts of which are already available.