Modern Compucon systems support NVMe devices and Intel Optane devices.
This article explains what they are in terms of technology.
stands for Non-Volatile Memory via PCI Express and is the latest
interface standard for (and specifically designed for) flash memory devices, set to replace SAS and SATA
(which earlier replaced SCSI and IDE respectively) for more traditional storage devices (mechanical). It can be considered the interface of a storage device with
the motherboard of a PC, but to be exact, it is the interface of a
storage device via PCIe to the CPU (whether it is via a PCIe slot on the
motherboard or via U.2 or M.2 physical interfaces).
- The data
transfer rate between the storage device and the motherboard is the
primary motivation for NVMe. Whilst SAS reached 12Gb per second of
theoretical peak transfer rate as of writing, NVMe reaches 32Gbps for
read or write by using 4 PCIe lanes on version 3 of the PCIe standard
(and more if desired or needed, as it can scale with more lanes of
- Owing to the removal of this interface data transfer
restriction, an SSD device with NVMe interface would be able to read or
write at the peak speed of NAND technology. That is, NAND medium
vendors would be able to improve the technology for higher data transfer
rates until reaching the interface limit. Example performance comparison of consumer devices with their respective interfaces:
- There are several
form factors of the interface as shown in the diagram. The top device
can be inserted directly onto the PCIe slot. The middle device goes
onto the mainboard via a specific M.2 slot. The bottom device goes into
a male-female connector (U.2) which is normally off the mainboard.
- There are many choices of NVMe
SSD on the market. An example is Samsung PM1725 which is based on NVMe
PCIe 3.0 x8 LP interface, and provides a storage size of 6.4TB, 5DWPD
(disk written per day) for 5 years, transfer rates of 6000MB/s and
2000MB/s for Sequential Read and Write respectively, and Random Read and
Write of 1000K and 120K IO per second respectively.
Note: The above information has been presented in the Compucon CPD seminar on 18 October 2017
top of the NVMe interface standard is the NVMe-over-Fabric standard for
connecting external storage devices onto the motherboard of a PC or
server. NVMe-over-Fabric standardization is going to happen over the
next couple of years as it takes time to get all the interoperability
worked out in the industry. Right now, the basics work but hot-plug and
error recovery would take time to become bullet proof.