SATA Express ports have appeared on 9-series Intel motherboards, and we've already played with one prototype storage device based on the next-gen interface. Now, another SATAe drive has appeared at the Computex show in Taiwan. This "demonstration prototype" was developed by WD, and there are two drives attached: a 4TB mechanical hard drive and a 128GB SSD.
The 3.5" dual-drive config appears to be similar to the Black² notebook hybrid WD introduced in November. That drive combines a 1TB HDD with a 128GB SSD, each of which can be used separately. Special drivers are required to see the Black²'s mechanical component, though. The SATAe prototype uses standard AHCI drivers, suggesting its tag-team implementation is more refined.
With 1GB/s of bandwidth at its disposal, the SATAe interface should be fast enough to keep up with an SSD/HDD tandem. SATAe also has interesting potential for SSHDs that use flash memory as a cache for mechanical storage. It will be interesting to see what sorts of solutions make it to market as actual products.