Recently I came across a new term, EDSFF. I don’t know what it means. After some research on it, I have a preliminary understanding. Now I will share my personal understanding in three parts:
1. The meaning and use of EDSFF itself
2. Comparative understanding of EDSFF and OCP NIC 3
3. The role of EDSFF in the future
1. The meaning and use of EDSFF itself
The meaning of EDSFF can be divided into two parts to look at EDS and FF (the purpose of this division is to help the next understanding, OCP NIC 3.0 is also divided into SFF and LFF), EDS is Enterprise and Data center SSD (enterprise-level and data center-level SSD), FF is the abbreviation of Form Factor, which together is the form factor of solid-state drives in enterprises and data centers . As the name suggests, it is not a hard drive for ordinary consumers. It looks like this:
Its role is to define the form factor for next-generation storage. Why do I say this? Let’s first review the advantages and disadvantages of existing hard drives. Traditional SATA 2.5-inch solid-state drives and mSATA are not fast enough, U.2 and U.3 are large, M.2 has poor heat dissipation, and none of the above support hot swapping. EDSFF defines different dimensions of long, short, wide and narrow to meet different business scenarios (it will not be expanded here, it is not the focus of this article. If you want to know more, please check other popular science articles).
2. Comparative understanding of EDSFF and OCP NIC 3
Let’s first look at the picture comparison of the two products:
It can be seen that OCP NIC3.0 (SFF Note: SFF here refers to small Form Factor. OCP NIC 3.0 is divided into SFF and LFF. L is the abbreviation of Large) is almost the same as the golden finger of EDSFF (E3), EDSFF There's just one part missing. Comparing the three product pictures of EDSFF, we can see that the difference between the gold fingers is to increase the width of the gold fingers.
Let’s take a look at the comparison of function definitions of Goldfinger:
Except for a slight difference in the definition in the red box, everything else is almost the same. The difference is that B7, B8, B9, and B42 of EDSFF are RFU and retain the function PIN, which means they are not used. A10 PIN, OCP NIC3.0 is used for presence detection of the inserted network card, and high and low levels are used for identification, while EDSFF, LED indication, is also used for high and low level identification.
Through comparison of definitions, it can be found that NIC 3.0 (SFF) has one more OCP Bay (28PIN) than EDSFF. The definition is also the same when extending downward to 4C x16 140PIN.
Check the relevant standards. The connectors used by both are the same specification (SFF-TA-1002), the same function definition (SFF-TA-1009), and the same PCIe interface.
Then compare through structural dimensions:
It can be seen from the comparison that the width of the two is the same.
3. The role of EDSFF in the future
The above-mentioned series of comparisons are intended to illustrate that EDSFF actually follows the OCP specifications. Because OCP specifications will be a trend for servers, all manufacturers will open their hardware to standard definitions, which is a benefit brought by OCP. In addition to being based on the OCP specification, EDSFF also has bandwidth and capacity issues to be solved. Future CPUs will have a lot of PCIe resources. After PCIe 4.0/5.0, memory and hard disks will all be a screen neck, and through Using PCIe interfaces will greatly improve computer performance, and PCIe-based memory and hard drives can release more CPU resources. It also greatly reduces the size of the motherboard, and the original memory slots will be replaced by PCIe memory pools. Similar to the picture below:
Summarize:
As the next generation of storage, EDSFF is compatible with the definition and structure of the Open Source Computing Project (OCP 3.0) and will work with various OCP accessories to improve server performance. This article explains the function and definition of EDSFF from the perspective of comparison with OCP NIC 3.0, hoping to help understand. (There is a lot of relevant knowledge about OCP3.0 on the Internet. If you don’t understand it, you can look it up yourself.)