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SATA Express - What is it?


SATA had a good run, thatís for sure. These neat little connectors with their thin cables did wonders for aesthetics and airflow, but most of all they liberated us from the pathetic speeds of PATA drives, topping out at 133 MB/s. First generation SATA interfaces were rated at 1.5Gb/s or 187.5 MB/s. Not such a great improvement, but each successive generation of SATA was planned to double that speed and indeed SATA III now theoretically will hit 6Gb/s or 750MB/s.

Thatís seemed like a pretty future proof plan since mechanical hard drives really hadnít been improving their performance in line with Mooreís law, which is only relevant to silicon electronics such as CPUs and RAM. That remains true, the fastest SATA III mechanical drives (excluding hybrid SSD drives) fall just short of 160 MB/s. A far cry from the 750 MB/s limit for that interface.

Sata Express Connector to the right of traditional SATA ports on ASUS motherboard

Then SSDs or Solid State Drives became affordable, mainstream products. Current high-end SSDs like the Samsung 850 Pro are solidly knocking on SATA IIIís upper limit. Thatís one single drive eating 550 MB/s in available bandwidth. It was clear that doubling the speed of SATA III would never keep up with the improvements in SSD technology, so instead of reinventing the wheel it was decided to embrace what had been a workaround for high-performance drives: PCI-express.

For a while it has been possible to get an SSD mounted on a PCI-express card using up to eight lanes for data transfer. These drives could blow SATA III out of the water, but the interface was never meant to host primary storage devices, which meant configuration could be tricky.

So SATA-express is just that, the standardisation of the PCI-express bus for storage device use. It provides and SSD or any other compatible device with multiple PCI-e lanes for data transfer. How fast is it? You better sit down for this: 1969 MB/s.

That provides some breathing room for the future, since current SSD speeds will have to quadruple before troubling the current limits of SATA-express.

If you look at the connector for SATA-express youíll notice that it looks like two SATA III connector glued together. Thatís no coincidence. You can connect either two SATA III devices or one SATA-express device to each connector. Itís fully backwards compatible, which means thereís no reason to hold back on upgrading. Those two SATA III drives will of course only run at 6Gb/s.

Which you need to be OK with, because as of now thereís arenít actually any SATA-express drives on the market. No one is sure exactly when the first drives will come, but it will be during 2015, unless something unforeseen happens.

If youíre in the market for a new computer or a motherboard upgrade thereís no reason not to go with SATA-express. When the new generation of drives arrive youíll be ready to simply slip them in and be blown away.

The TitanUS X199 is our first new build featuring SATA-Express. Youíll find much more to like about it, so head over to the product section to see what this mighty machine has to offer.