The future of Serial ATA: SATA Express, NGFF and NVM Express

he organization responsible for the SATA standard is getting ready for the future of computers in a number of different ways. Today we will take a closer look at SATA Express, NGFF and NVM Express.

State of the art SSDs can nowadays easily reach the maximum transfer rate of the SATA 600 interface. As the name suggests, the theoretical max transfer rate is 600MB/s, but in practice it's around 550MB/s that's possible.

Many SSDs approach that number even for writing by now. An additional factor is the software-based control of SATA devices, the so-called AHCI (Advance Host Controller Interface) standard.

It's not very well-suited for sending multiple tasks simultaneously, while SSDs are very adept at just that. So the Serial ATA 600 bus is really the limiting factor here. If manufacturers want to make faster SSDs, we'll soon need a new interface.

Many are therefore looking forward to a possible Serial ATA 1200 standard, the logical next step after SATA150, SATA300 and SATA600. The Serial ATA International Organization, the consortium responsible for the interface, has done its research about what the next standard will be.

The professional version of SATA, the Serial Attached SCSI or SAS interface, now goes up to 1.2GB/s. This experience also taught them that it's not a very simple feat to achieve the higher speed for desktops and laptops.

Controllers for a SATA1200 interface would be much more complex than those for SATA600, just like the latest generation SAS controllers are much more complex than their predecessors. This requires larger chips, which makes the controllers much more expensive. Existing cables also will not be enough for a SATA1200 interface. Compatibility issues are therefore a problem.

To keep things simple and affordable, it's been decided to postpone SATA1200 for a while. This also has to do with the fact that not many devices could actually take advantage of the faster standard yet, so a switch now would be premature as hard disks and entry-level SSDs don't come close to the SATA600 limit yet.

Read the rest of this featured article on hardware.info.