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M. 2. Introduction to Interface Knowledge and What is the Interface Protocol

Date:November 15th,2023 View:105
In the storage industry, storage devices are involved in various interface issues, and different interfaces cater to the products required by different environments. For example, at this moment, we need to popularize a storage interface with everyone& Flash; M. 2.
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Interface appearance

M. The gold finger with 2 interfaces is divided into B-Key and M-Key, which respectively correspond to" Socket 2” And&quo; Socket 3”. Usually, Socket 2 runs through SATA and PCIE X2 channels, while Socket 3 runs through PCIE X4 channels. This means that the link transmission bandwidth of Socket 3 is higher than that of Socket 2. (Bandwidth is not determined by the interface, but by the protocol, as will be discussed below!)

Socket 2=B key, supports Sata, PCIe x2

Socket 3=M key, supports Sata, PCIe x4

M. 2 interface appearance

The B-Key anti daze key is on the left side of the slot, and the M-Key is on the right side. There is a difference in the number of pins between the two types of pins, so the B-Key cannot be installed in the M-Key slot in reverse< Br/>

M. 2 interfaces B-KEY and Mkey

At the beginning of product design, B-Key storage products can only be applied to the motherboard corresponding to the B-Key interface, and M-Key products can only be applied to devices in the M-Key slot. With the advancement of technology, the M-Key interface on the computer motherboard has surpassed the B-Key interface, to the extent that a combination of the two has been developed; B& M Key”, This interface is a commonly used interface for M.2 SATA channel solid-state drives that we can still purchase on the market today (2023)< Br/>

Interface protocol

The essence of the protocol is to standardize the channel specifications for storing data, that is, the M.2 Socket 2 products use the SATA channel and PCIE X2 channel, while the M.2 Socket 3 products use the SATA channel and PCIE X4 channel standards< Br/>

Based on the current products on the market, the solid-state drives we can buy for M.2 PCIE NVME all use the PCIE X4 channel, while the solid-state drives for M.2 SATA use the SATA channel. The former corresponds to M.2 Socket 3, while the latter corresponds to M.2 Socket 2< Br/>

In addition, these protocols also have their own names, AHCI and NVME


Simply put, NVME is a new storage data exchange protocol that has emerged in recent years. Its speed is determined by the bandwidth of PCIE, which currently has the strongest performance, such as PCIE 5.0/PCIE 4.0/PCIE 3.0. The theoretical bandwidth of a single channel in PCIE 3.0 can reach 8GB, so compared to the 6GB bandwidth of SATA channels, it is naturally far inferior. So if you are choosing a solid-state drive, try to choose a high-performance NVME protocol solid-state drive< Br/>

Interface specifications

When we purchase solid-state drives in stores and on display, merchants usually refer to specifications such as 2242/2280, which refers to their specifications< Br/>

2242=22 * 42mm

2280=22 * 80mm

2260=22 * 60mm

There are also some other specifications, such as 2230, used in some particularly compact devices, mainly to save space and enjoy the smoothness of high-performance bandwidth< Br/>

Seten is a trusted server hardware and solution provider in the global digital process Apply&quo; Spot+Agency&# quo; Model, rapid response, specialized management, and professional and efficient services to assist partners in achieving digital upgrades and winning the new data era. Saitern has three main product lines: Samsung SSD, Memory (RDIMM), SOLIDIGM SSD, and Broadcom network products. It is also an agent for NVIDIA's Melosi network products and the complete XFusion server.