An Introduction to Dual-Port NVMe SSD.

March 31st 2016. It’s last day of Q1 and it’s full of surprises. If you missed the announcement, take a chance and spend a minute reading press release. I’m proud today; we at NSG (Non-volatile Memory Solutions Group) have just released new products, based on very new to the industry technologies.It comes first with a first Intel 3D NAND based NVMe SSD for Data Center. My peer Vivek Sarathy is excited about its performance and similar to SATA price in his blog.

That’s not just it. Another new SSD family is announced, Intel® SSD DC D3700 / D3600 Series. These are very special SSDs to address dual-port PCI Express* SSDs High Availability designs. This architecture is used to address a critical redundancy and failover, protecting against to every single path failure.

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In reality that means that the SSD has a capability to be connected to two hosts at a time, shown as Storage Controller on the diagram. They can be connected directly to a host CPU or via PCIe switch topology if higher SSD count is required. If you’re familiar with Enterprise Storage HA designs based on SAS, this looks very similar but implemented with PCIe bus.

Dual-Port NVMe extensions were added to original specification with NVMe 1.1 revision few years ago. Since that time few vendors have announced products and solutions based on that technology. It’s ramping up now but the eco-system is new and very focused on addressing specific problems. These problems are common for Enterprise Storage (Scale Up Storage) and some other areas such as HPC Storage. By the way, please, take a look on my other peer’s blog, Allen Scheer “What Kind of Storage Buyer Are You?”‌.

Dual-port NVMe is another way for HA topologies. This also means system design of single port NVMe SSDs needs the re-architecture. As the product SSD is available in single form factor – 2.5” U.2, sharing similar connector as before. That also means, it still has 4 lanes of PCIe Gen3 as in original design, but for dual-port designs they are split into the pair by 2, so 2 x PCIe Gen3 x2. In order to support new connectivity, system must have new backplane which have a PCIe properly routed to two hosts with or without PCIe switches.

There is another advantage of D3700 / D3600 series over current single port SSDs. These drives are based on NVMe 1.2 specification, which introduces new features for all NVMe SSDs.


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The one of those is multiple Namespace support. You can make here an analogy with SCSI LUNs, so a single SSD can be partitioned in multiple hardware partitions where a namespace can be assigned to two hosts or otherwise dedicated to a single host. This allows isolating the partition from another host until a critical failure on assigned host happened.


Looks complicated? Yes, it’s complex design changes but they are paid back right away by performance improvement. This also means to make the product successful Intel partnership with hardware and software vendors to enable the support of new drives. I’m very happy to see storage innovators such as XIO and E8 Storage working with Intel to show the benefits proof points in enterprise storage solutions as followings. More works are going on with Quanta, Wistron, AIC and others storage partners.

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Intel SSD DC D3700 vs. SAS SSD performance comparison.  Source – XIO.  Configuration - External Host with windows server 2008 running. External host specifications: HP DL360, G7 with dual intel E5-2620 and 25GB ram. Storage array system using E52699v3 with 40*Intel DC D3700 10 DWPD 800GB & Storage array system using E52699v3 with  40* SAS 10 DWPD 400GB . Test - 8K transfer with 80/20 Read/Write workload on QD 1,2,4 accessing 1 volume on the shared storage array.  Measurements taken on IOMeter.

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E8 Storage high availability. Source – E8.  Configuration: 4 host connected to E8 PoC storage system: 2 E5 2650v3 CPU and 24 intel DC D3700 800GB Drive. Performance measured by 8FIO threads per host, QD=32 per thread, 4k 100% Random read.

Can’t wait sharing more with you. See you at IDF16 at Dual-Port NVMe class.

Published on Categories Data CenterTags
Andrey Kudryavtsev

About Andrey Kudryavtsev

Andrey Kudryavtsev is SSD Solution Architect in the NVM Solution Group at Intel. His main focus is the HPC area, where he helps end-customers and eco system partners to utilize the benefits of modern storage technologies and accelerate the SSD adoption for NVMe. He holds more than 12 years of total server experience, the last 10 years working for Intel. He is the guru of engineering creativity and is an influence in his field. He graduated from Nizhny Novgorod State University in Russia by Computer Science in 2004. Outside of work, he is the owner and coauthor of many experimental technologies in music, musical instruments, and multi-touch surfaces.