Raidon showed off their new HyBrid drive enclosure recently, a strange combination of an SSD drive enclosure and a SATA enclosure. It’s not an external device mind you, but rather an internal drive cage that will read and write to the SSD, and then mirror the process to the SATA drive.
Raidon stated that while the HyBrid system is not a RAID system, it is possible to restore data from the standard hard drive if the SSD were to fail. The SSD drive will be removable and can be used without the HyBrid system, you would just put the SSD into another enclosure or connect directly to a controller. Raidon didn’t disclose available sizes or pricing on the HyBrid, but it should be available this coming April as an internal device, and then as an external device later this year.