WD combines 128GB SSD with 4TB HDD and PCI-e interface

Western Digital has shown a hybrid drive in which a 4TB hard drive is combined with a 128GB SSD. The hybrid drive prototype uses a PCI-E 2.0 x2 interface via a SATA Express connector.

WD’s hybrid test drive is on display at the company’s CES booth. Despite using a pci-e 2.0 x2 interface, the used JMicron sata-600 controller limits the maximum throughput to about 550MB/s. By combining two hybrid drives in a raid 0 setup, throughput speeds of approximately 1GB/s are possible.

According to Anandtech, the SSD and the hard disk can only be accessed as separate storage volumes. WD is said to be working on a mechanism whereby the 128GB SSD can be used for caching purposes. It is still unclear whether and if so when WD will launch hybrid drives based on the prototype. It is also conceivable that Western Digital eventually opts for a native PCI-e controller chip, so that higher speeds are possible.