Ethernet SSD-Enabled Approach
Storage scaling using Ethernet SSDs
When we left off, I had just finished detailing the advantages of an Ethernet SSD-based approach to storage scaling when compared to using conventional SSDs. Now, let’s take a look at what the future holds in terms of next gen interface standards and connector compatibility.
Future Proof Interface Speed Transitions
Currently, the NVMe® interface is the only interface capable of scaling to interface throughput higher than 24 gigabits per second (Gbps).However, as the standard PCIe® progresses to Gen.4 through Gen.5 and Gen.6, there are additional connector transitions, PCIe switch transitions, HBA transitions, RAID card transitions, etc. that need to all be in sync in order to realize the promise of future NVMe interface transitions. Since the Ethernet ecosystem already has a roadmap for future interface technology transitions, Ethernet SSDs can leverage these transitions as the underlying hardware and software enhancements required to enable 50Gpbs, 100Gbps and 400Gbps – which will be readily available for Ethernet SSDs to adopt. This allows a smoother path for Ethernet SSDs to transition to higher speeds.
Commonality in Connector Technology
Standard dual-port, enterprise-grade NVMe SSDs currently use the SFF-8639 connector. As the PCIe interface progresses through Gen.4 to Gen.5 and Gen.6, the SFF-8639 connector will no longer be compatible. New connectors will be needed, starting with PCIe Gen.5 as defined by the SFF-TA-1002 specification. SFF-TA-1002 is rated for 56G PAM-4 or 112Gbps maximum interface throughput. This same connector can be used for Ethernet SSDs as well, providing tremendous leverage and infrastructure synergies for our customers. In the short term, we have enabled Ethernet SSDs to continue to be compatible with the SFF-8639 connector and, as PCIe progresses, the transition to TA-1002 will ensure continued connector compatibility across PCIe and Ethernet interfaces. This bears repeating. No new connector is required for Ethernet SSDs.
Cost Effectiveness with Ethernet SSDs
Ethernet has evolved over the past 4 decades to become the networking technology of choice for the world’s digital connectivity. Ethernet is scalable, resilient, cost effective and ubiquitous. Scaling problems, security, fault tolerance, serviceability, supply chain, standardization and the entire ecosystem around Ethernet is very mature. It is so mature that for most of our customers, Ethernet connectivity is the most common mid-to-long haul solution to move data across global locations. However, this is only the case ‘outside the box’ as there are various other connectivity and data transfer protocols ‘inside the box’.
Summary
In summary, Ethernet SSDs enable a simplified system architecture for storage expansion that is cost effective and scalable. New connectors are not needed, as current and future generations of Ethernet SSDs have been designed to be fully compatible with NVMe connectors via the SFF-TA-1002 specification. Ethernet SSDs enable efficient storage scaling without the need to add external CPU, DRAM or other peripherals currently required for storage expansion - even though they may not be needed. If the host system is updated to handle new storage expansion EBOFs, this approach can be used to cost-effectively scale storage almost indefinitely.
For additional capabilities and interoperability of Ethernet SSDs, SNIA has put together a nice tutorial and Q&A here:
https://sniansfblog.org/25-questions-and-answers-on-ethernet-attached-ssds/
Notes:
PCI Express and PCIe are registered trademarks of PCI-SIG.
NVM Express and NVMe are registered trademarks of NVM Express, Inc.
NVMe-oF and NVMe-MI are trademarks of NVM Express, Inc.
Product image may represent a design model.
In every mention of a KIOXIA product: Definition of capacity - KIOXIA Corporation defines a megabyte (MB) as 1,000,000 bytes, a gigabyte (GB) as 1,000,000,000 bytes and a terabyte (TB) as 1,000,000,000,000 bytes. A computer operating system, however, reports storage capacity using powers of 2 for the definition of 1Gb = 230 bits = 1,073,741,824 bits, 1GB = 230 bytes = 1,073,741,824 bytes and 1TB = 240 bytes = 1,099,511,627,776 bytes and therefore shows less storage capacity. Available storage capacity (including examples of various media files) will vary based on file size, formatting, settings, software and operating system, and/or pre-installed software applications, or media content. Actual formatted capacity may vary.
Read and write speed may vary depending on the host device, read and write conditions, and file size.
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