The Enterprise and Datacenter SSD Form Factor household of requirements is now about three years previous, and continues to evolve. The EDSFF type issue choices are gaining traction in a number of markets, and classes realized by early adopters are nonetheless driving tweaks to the specs. The myriad variations below the EDSFF umbrella haven’t been simplified a lot, however not less than the temporary format battle between the EDSFF E1.S type issue and Samsung’s NF1 has concluded, with Samsung now supporting and contributing to the E1.S normal. As EDSFF adoption will increase, we’ll in all probability see a number of variants fall into irrelevance, as occurred to a few of the much less fashionable M.2 card sizes. But even as soon as it is clear which members of the EDSFF household are succeeding out there, the much less fashionable choices will in all probability stay a part of the requirements paperwork.
The EDSFF flavors all share a standard connector normal, which originated because the Gen-Z Scalable Connector Standard and has been adopted by a number of different requirements. The Gen-Z connector gives a lot increased density than conventional PCIe slots, provides the 12V energy that M.2 lacks, and is comparatively future-proof by providing ample sign integrity for future variations of PCIe. The EDSFF requirements outline three sizes of the connector and pinouts for PCIe x4, x8 and x16 hyperlinks.
The EDSFF type components are available two heights: sized for 1U servers are E1.S and E1.L, the brief and lengthy derivatives of the Intel Ruler idea. For 2U servers, the E3 sizes are just like the present 2.5″ drive type issue.
Reboot Of E3
The most vital modifications previously yr have been to the E3 type components. Earlier this month model 2.Zero of the E3 type issue spec was revealed, breaking backwards compatibility with model 1.Zero from 2018. The motivation for the incompatible modifications got here from the Open Compute Project (OCP) NIC 3.Zero specification, which has comparable dimensions however makes use of a brand new variant of the Gen-Z connector: OCP added a fourth tab with 28 additional contacts to hold numerous sideband alerts not included within the 4c (x16) model of the connector. The E3.S type issue was stretched a bit to match the scale of the OCP NIC 3.Zero normal, and the connector location was moved to be appropriate with the OCP NIC 3.0. With the brand new model of the EDSFF E3 spec, it is now potential for servers to offer slots that may fulfill both position.
The E3 type components are probably the most succesful and versatile within the EDSFF. They assist as much as PCIe x16 connections, although most SSDs will proceed to stay with simply x4. The E3.L 2T provides comparable bodily quantity and TDP to a half-height half-length PCIe add-in card. The E3.S in two thicknesses is barely bigger than the 2 widespread thicknesses for U.2/U.Three SSDs, however E3.S provides higher cooling and the potential of extra PCIe lanes. The newly stretched E3.S can also be now massive sufficient that an E1.S PCB may be mounted inside an E3.S case, offering a fast and simple path for compatibility between the 2 heights.
| E3 model 2.0 Form Factor variants SFF-TA-1008 |
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| Form Factor | Approximate Dimensions (mm) |
Front Drive Bays in 2U |
Typical SSD Power Limit |
Max PCIe Lanes |
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| E3.S | 76 | 113 | 7.5 | 48 | 25 W | x16 | |||
| E3.S 2T | 76 | 113 | 16.8 | 24 | 40 W | x16 | |||
| E3.L | 76 | 142 | 7.5 | 48 | 40 W | x16 | |||
| E3.L 2T | 76 | 142 | 16.8 | 24 | 70 W | x16 | |||
| PCIe HHHL | 68 | 168 | 19 | 40-75 W | x16 | ||||
| 2.5″ U.2 | 7mm | 70 | 100 | 7 | 48 | 12 W | x4 | ||
| 15mm | 70 | 100 | 15 | 24 | 25 W | x4 | |||
| 3.5″ U.2 (theoretical) | 102 | 147 | 26 | 12 | x4 | ||||
| M.2 22110 | 22 | 110 | 5 | 8.25 W | x4 | ||||
When the EDSFF household launched, a lot of the early…
