What exactly is u.2 SSD?

SSD interface is diverse, the mainstream SATA3.0 interface most common, the recent very hot M.2/PCI-E interface, once extremely the SSD most loves to use the mSATA interface, now has appeared a u.2 interface, must pedal m.2, replaces Sata, becomes the future SSD mainstream choice? What exactly is the U.2 interface? Today's SSD story, we'll talk about u.2 SSD.

　　What is the U.2 interface?

The U.2 interface, formerly called SFF-8639, is driven by Intel single-handedly. Essentially SATA Express, and the SATA-E physical interface is transformed via the SATA 6Gbps interface, somewhat similar to the SAS interface. It uses 2 SATA 6Gbps connectors and a mini SATA interface with only 4pin pins, where the small interface can only be connected to the PCI-E line, the biggest benefit is to maintain backward compatibility, because the current number of SATA e hard disk is too small.

The U.2 interface is designed to be similar to SATA-E, using the existing physical interface as much as possible, but with faster bandwidth, from PCI-E X2 to PCI-E 3.0 x4, and many new protocol support, such as NVMe, which are not available on SATA E interfaces. It can be said that u.2 is actually SATA E's complete body.

　　Why is it called u.2?

U.2 Interface Board End Interface

M.2 was first called NGFF. U.2 was first called SFF-8639. SFF-8639, because this name is too uncommon, obviously not easy to be remembered by the user, this temporary address soon has a formal name: u.2.

　　What are the features of the u.2 interface?

With the latest u.2 connectors on the latest 0 series motherboards

U.2 's device-side interface incorporates the features of SATA and SAS interfaces, with pins filling the slots left by the SATA connector and reserving the L-type anti-stay design, so it can be compatible with SATA, SAS and SATA e specifications, and the motherboard is the mini SAS (SFF-8643) interface,　　The u.2 line on the device side is connected to the SATA power supply and one end is connected to the data port on the u.2 hard drive. The biggest feature of the U.2 interface is the support of the NVME standard protocol, high speed, low latency, low power consumption, bandwidth PCI-E 3.0 x4, theoretical transmission speed of up to 32Gbps, and SATA only 6Gbps, more than SATA 5 times times faster.

　　What does m.2 have to do with u.2 interfaces?

U.2 SSD can be converted into m.2 interface

M.2, u.2 can go with PCI-E 3.0 x4 Channel, also can support nvme norms, some people say m.2 and u.2 relationship is similar to msata and SATA relationship. The former solves the problem of mSATA interface, mainly for small mini devices, such as one machine, two in one deformation, notebook, mini machine, etc., of course, many motherboards also have it. And u.2 is expected to replace SATA, from the enterprise-level to consumer-level gradually popularized.

U.2 can be converted to m.2 interface (mSATA can also convert to SATA), as long as the M.2 interface is also 32Gbps bandwidth, this transfer will not have performance loss.

　　What products currently support the U.2 interface?

Intel 750 Series SSD supports the U.2 interface with one of the interface types

One common feature of enterprise-class solid-state drives, such as GST Ultrastar SN100, OCZ z-drive 6000, is that they provide two morphological specifications, one is the traditional PCI-E expansion card style and the other is the 2.5-inch disk style of the u.2 interface.

However, the average consumer is now only able to buy u.2 SSD, only the Intel 750 series, with a total of 400G and 1.2TB two capacity. 400GB of continuous reading and writing up to 2.2gb/s, 900mb/s, Random Read and write up to 430000 ioPS, 230000 ioPS. 1.2TB can achieve 2.4gb/s, 1.2gb/s, 440000 ioPS, 290000 ioPS, performance is very strong.

In the motherboard, Asus, Gigabyte, MSI, Hua Yin and other vendors have announced the support of the u.2, and demonstrated the new u.2 data line, u.2-m.2 converter. Like the current Asus ROG Maximus VIII Extreme motherboard, there is a u.2 interface.

　　Will the u.2 interface become a mainstream interface in the future?

Will it replace the SATA connector?

After the new NVME specification, the performance of SSDs has greatly improved, exceeding 600mb/s is too normal, making the traditional sata6gbps interface has been outdated, become the bottleneck that restricts the development of SSD performance.

It has been suggested that the SATA-E interface replaces the SATA 6Gbps, but ultimately fails to take shape, mainly because the advantages of the SATA-E interface are not so obvious. and to the u.2 interface, walk PCI-E 3.0x4 channel, support NVME specifications, theoretical bandwidth doubled, in power supply and other aspects have done optimization, is expected to replicate in the Machine field m.2 interface in the mobile market success, the future replacement SATA interface is also never possible.

At this stage, however, this may not become a reality. Although u.2 has many attractive advantages, but the motherboard support is not enough, and SATA has been the motherboard has been standard, want to let the motherboard manufacturers will be SATA to u.2, this part of the cost, including materials, technology research and development, production, etc., let who bear it? Besides, the current u.2 Interface SSD is pitiful. The consumer-grade u.2 SSD is available only to the Intel family.