As the enterprise SSD matures it is shedding its legacy hard-disk identity one technology at a time. SATA has been replaced by PCI Express. Serial buses have given way to parallel data flow, and the 2.5-inch form factor is going to give way to a new design for greater chip density and cooling.\nKioxia America, formerly Toshiba, has demonstrated a fully functional E3.S SSD called Enterprise and Datacenter SSD Form Factor (EDSFF), also known as E3. Both form factors are being developed by the Storage Network Infrastructure Association (SNIA) consortium.\nThe E3.L has a long, thin shape like a ruler. Intel demonstrated a prototype ruler design three years ago, but it was a prototype and never went anywhere.\nEDSFF has been designed from the ground up to support SSDs in all-flash arrays for both cloud and enterprise data centers using a new form factor rather than the standard 2.5-inch drive. While that form factor works well in laptops, it was limiting for servers because of how chips could be placed.\nThe current drive uses eight lanes of PCI Express Gen4 networking and draws 28 watts of power, more than the 5 watts a regular SSD consumes, but it has more chips. The PCI Express Gen5 drives of the future will use 40 watts.\nWhat does that extra power get you? For starters, better signal integrity to deliver the performance promised by PCIe Gen 5.0 and beyond, and the ability to power more chips. That also means a change in cooling methods.\nFeaturing one common connector, this form-factor standard for PCIe-based devices, such as NVMe SSDs, graphics processing units (GPU) and network interface cards (NIC), enables a complete array of footprint, power and capacity options, offering unprecedented system flexibility.\nOn top of the Long and Short form factors, the E3s come in thin (7.5mm) and thick (16.8mm) forms with different amounts of memory packed into them.\nThe E3.L is more than a foot long and is designed to slide into a 1U rack and be cooled by the server fans. There is also the option for 9.5mm or 18mm heat sinks on the ruler. The long, thin design of the E3.L also improves data-center serviceability, making it easier to add or remove drives, which are designed to be hot pluggable and front-access serviceable.\nKioxia has not said when it expects to ship the EDSFF.