Combines a standard spinning platter drive (HDD) in 250, 320 or 500 gigabyte versions with four gigs of single-level cell (read: robust) Flash memory. Right now these are just about doubling the cost of standard drives with similar capacity.
The result is a combined drive that approaches the performance of solid state drives, but at a fraction of the price. According to Seagate’s own tests, the Momentus XT is 80% faster than a traditional notebook hard drive, and 20% faster than an ultra high-performance 10,000 RPM HDD.
The speed boost is due almost entirely to the drive’s Adaptive Memory algorithm, which learns which applications and files a user accesses most, and dumps those in the 4 GB of flash memory. Flash has 150 times the access speed of a traditional hard drive, but only 2 times the read/write bandwidth.
The technique of balancing a cache of expensive flash memory, which is great at randomly accessing many small files, with a large hard drive, which is many times cheaper per gigabyte and is good at reading and writing large files, mirrors a similar approach currently being explored in the data center.
Seagate’s hybrid drive. Credit: Seagate.