First, NAND based SSDs arrived in SATA, SAS, and PCIe form factors, almost a decade ago. In 2015, NVMe became widely available, in various shapes and sizes, including U.2 (looks like a thick metal 2.5" laptop drive), and HHHL (Half Height Half Length) PCIe cards, aka AIC (Add In Card)s. With the recent release of Intel xeon Scalable Processors (Purley), we have new servers that include NVMe cards in those hot-swap 2.5" drive bays, such as the 2U Dell EMC PowerEdge R740xd, for example.

But what if you're working within the constraints of a 1U server design? In advance of the Intel Flash Memory Summit running from August 8-10 in Santa Clara CA last week, a bunch of announcements were already made on August 7, including:

“Ruler” form factor for Intel® SSDs, an all-new solid state drive form factor enabling up to 1PB of storage in a 1U server rack in the future.

The world’s most advanced dual port portfolio: Intel® Optane™ technology dual port SSDs and Intel® 3D NAND dual port SSDs for mission-critical applications.

An updated SATA family of SSDs for data center, targeted at HDD replacement.

Intel Further Delivers on Storage Transformation with New SSD Form Factor and Innovative Designs ‘Ruler’ Form Factor for Intel SSDs Credit - Intel Corporation. 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 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. Both Intel Optane SSDs and Intel® 3D NAND SSDs in the “ruler” form factor will come to market in the near future.

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Dual Port SSDs Dual port Intel Optane SSDs and Intel® 3D NAND SSDs offer critical redundancy and failover, protecting against multiple paths to failure for mission-critical and high-availability applications. Dual port SSDs replace SAS SSDs and HDDs and, with new storage technologies, deliver more IOPS, more bandwidth and lower latency than SAS SSDs. Dual port Intel® SSD DC D4500, D4502 and D4600 Series will be available starting in 2017’s third quarter. SATA SSDs for Data Centers Credit - Intel Corporation. The Intel® SSD DC S4500 and S4600 Series combine a new Intel-developed SATA controller, innovative SATA firmware and the industry’s highest density 32-layer 3D NAND. These storage-inspired SSDs preserve legacy infrastructure, ensuring a simple transition from hard disk drives to SSDs, while enabling data centers to reduce storage cost, increase server efficiency and minimize service disruptions. The new members of the second-generation Intel®3D NAND SSD family are available now.

It would seem that M.2 NVMe "gumstick" has the best shot at sticking around for a while, tucking into a little slot right there on compact Intel NUC and Xeon D motherboards, along with even smaller form-factor devices like laptops. I would hope to see standardization on ejectable PCIe media, but I won't be holding my breath, with server vendors intent on a variety of proprietary drive carrier styles

If a consumer version of the 2.5" DC S4600 3.8TB arrives, and if prices drop low enough, that would be an appealing alternative to the rather common 4TB to 10TB spinning 3.5" drives that have fallen so far in price lately. So far, the only S4600 Series that has surfaced on Amazon is the 960GB, listing a "Date First Available" of August 11, 2017. The 1.9TB S4500 is also on Amazon now.

Page 6 of the presentation deck below couldn't make it more clear that Intel wishes for the Ruler to conquer the U.2 form-factor. Such a victory would remove those U.2 drive carriers from server designs, a loss I figure OEMs would mourn more than server owners.

More information on Intel's new Data Center SSDs is available at Intel's Solid State Drives site, see also all Intel SSDs, and the Data Center Intel® SSD Data Center Family.

Here's the PDF source of the screenshots below.

I obtained written permission from Intel to publish this presentation.

VMworld 2017 US - at Intel, Juan Fernandez shows NVMe SSDs, Ruler & Optane P4800X in PCIe & U.2

New article at Intel IT Peer Network:

Intel’s New Ruler Form Factor: The Shape of the Future

Jan 12 2018 by James Myers ...

So the form of early SSDs had nothing to do with what makes a good SSD. Instead, that design came from an older technology. Form factors did change, though. They eventually evolved into the M.2 design in 2010 and the PCIe/U.2 in 2012. (Fun fact: That’s my hand in the Wikipedia entry!) 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. But, it’s time for a change.

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Supermicro announcement:

Supermicro Introduces Next-Generation Storage Form Factor with New Intel "Ruler" All-Flash NVMe 1U Server and JBOF

Nov 28 2017 by Super Micro Computer, Inc.

Finally, going back a little further, far more details (and great pictures) here: