Solid state drives and hard disk drives are, currently, selling as completely distinct entities, but there were, in the past, attempts to somehow combine the benefits of both worlds. Verily, it is quite logical that one would want a storage unit as capacious as an HDD but as fast as an SSD. The first attempts at such a conciliation were made in 2006 and met with utter failure. Seagate, however, believes that the concept is sound, which is why it prepared the Momentus XT hybrid drives.
The Momentus XT are, essentially, hard disk drives with some single-level cell (SLC) NAND Flash memory chips built into them. Those chips provide about 4GB of Flash memory, meant to store the most often used files. This would allow for significantly shorter access times and, most likely, better boot-up times as well. In the meantime, the platters will be sure to provide enough space for everything else.
4GB is a major improvement over the 256MB of Flash storage that the first such hybrid drives came with. Of course, on desktops, such a device would not be practical, because users could simply buy an SSD boot drive and be done with it.
On the laptop front, however, hybrid drives may actually gain traction, which is why Seagate's Momentus XT feature the 2.5-inch form factor. Furthermore, implementation of flash memory may even bring some power-efficiency benefits.
Seagate's Momentus XT hybrid drives will operate on the SATA 3.0 Gbps interface and will have a rotary speed of 7200RPM. They will be announced next week, on May 26, will boast capacities of 250GB, 320GB and 500GB, and are already up for pre-order in Europe, at 93 Euro, 100 Euro and 124 Euro, respectively. One might notice that regular 2.5-inch drives are about 40 to 60 percent cheaper, depending on capacity. Nevertheless, the newcomers may still prove quite convenient, as long as they show a visible performance boost.
Seagate Resurrects HDD/SSD Hybrid Drives, Preps Momentus XT
Relatively cheap storage with low access times
... so hot right now