EDSFF E1 Form Factor

KIOXIA Corporation provides next-generation PCIe® 4.0 data center NVMe™ SSDs with its XD6 and XD7P Series, which are designed to the Open Compute Project® (OCP) Datacenter NVMe™ SSD specification and available in E1.S form factors. There are a number of key reasons why these new EDSFF E1.S SSDs can enable a data center server architecture to adapt to changes, but the top five supported by KIOXIA include:

Higher Performance / Higher Power Budget vs. M.2 Devices: More than doubles the power budget versus M.2 devices, enabling E1.S SSDs to saturate PCIe® Gen4 performance.

Standardized Thermal Solutions: Improves interoperability across vendors and platforms while providing the flexibility to select the right balance of cooling and storage density through different E1.S heatsink options.

Improved Physical Serviceability: Vastly improves serviceability with hot plug support that no longer requires an entire server to be taken down in order to replace a single SSD.

Designed to Better Accommodate NAND Flash Memory Packages: Wider PCB design enables optimized orientation of the NAND flash memory packages, providing headroom for higher capacity drives.

Supported by Leading Hyperscalers: Meta™ and Microsoft®, leading authors of the OCP Datacenter NVMe™ SSD specification, are specifying E1.S designs on upcoming OCP platforms, promoting industry-wide adoption.

E1 - Hyperscale Servers and Storage

E1 EDSFF size and dimension E1 EDSFF size and dimension
Type Thickness (mm) Width (mm) Length (mm) Max Power (W)
E1.S 5.9 mm 5.9 31.5 111.49 12
E1.S 8 mm with heat spreader 8.01 16
E1.S 9.5 mm with symmetric enclosure 9.5 33.75 118.75 20
E1.S 15 mm with asymmetric heatsink 15 25
E1.S 25 mm with asymmetric heatsink 25
E1.L 9.5 mm with symmetric enclosure 9.5 38.4 318.75 25
E1.L 18 mm with symmetric heatsink 18 40

EDSFF E1.S Use Cases

E1.S form factors are well-suited for these use cases:

E1.S (9.5 mm)

Target System Small footprint systems
Examples Blade servers; Edge compute and storage systems; Dense, scaled servers
Primary Need(s) Performance; Excellent thermal capabilities
Use(s) 2.5-inch and M.2 replacement
Typical Configuration 6 to 12 E1.S SSDs
A server rack with E1.S 9.5mm

E1.S (15 mm)

Target System 1U/2U/4U and special-purpose systems
Examples Compute blades and systems; Performance and capacity-optimized storage systems; Artificial Intelligence/Machine Learning (AI/ML) and High Performance Computing (HPC) systems; Edge systems
Primary Need(s) Scalable performance and capacity; Optimized thermal performance
Use(s) 2.5-inch and M.2 replacement for boot and primary storage
Typical Configuration 2 to 32 E1.S SSDs
A server rack with E1.S 15 mm

E1.S (25 mm)

Target System 2U and larger systems
Examples Storage appliances; Input/Output (I/O) and storage-rich servers / databases; Performance-oriented storage systems
Primary Need(s) Scalability of performance with capacity; Lower cost per performance
Use(s) Mainstream 2.5-inch replacement
Typical Configuration 36 to 64 E1.S SSDs
A server rack with E1.S 25 mm



KIOXIA XD6 E1.S 9.5mm, 15mm, and 25mm product image


KIOXIA XD7P E1.S 9.5mm, 15mm, and 25mm product image
KIOXIA SSD Series Form Factor Endurance Interface Storage Capacity (GB) Sequential Read/Write (MB/s) Random Read/Write (IOPS)
EDSFF E1.S Read Intensive
(1 DWPD for 5 years)
PCIe® Gen4 x4, NVMe™ 2.0 1,920
Up to
7,200 / 4,800
Up to
1,650K / 200K
PCIe® Gen4 x4, NVMe™ 1.3c 1,920
Up to
6,500 / 2,350
Up to
880K / 90K

Companies Offering EDSFF E1.S-enabled Platforms

EDSFF E1.S server and storage platforms are becoming available in the market. Here are some E1.S enabled products that are announced or currently available, as of September 2023. 

Learn and Evaluate

  • PCIe is a registered trademark of PCI-SIG.
  • NVMe is a registered or unregistered mark of NVM Express, Inc. in the United States and other countries.
  • Other company names, product names, and service names may be trademarks of third-party companies.
  • All rights reserved. Information, including product specifications, content of services, and contact information is believed to be accurate as of October, 2023, but is subject to change without prior notice. Technical and application information contained here is subject to the most recent applicable KIOXIA product specifications.