Microsoft would have us believing that the hybrid disk drives (containing a standard magnetic disc drive, some Flash memory and the usual cache memory) are the solution to all world’s problems (including hunger and poverty), the culmination of technology finally allowed by Windows Vista.
The basic principle of adding Flash memory to a disk drive is to provide some kind of cache memory buried less deeply into the disk system and that the Operating System (Windows Vista) would be able to use at will to improve disk system performance.
Thanks! But no thanks! It increase the cost and the complexity of the whole PC system. Where cache memory was a simple mean for the disk sub-system to optimize its operation without asking anything from the Operating System (it only sees a slightly faster drive), Flash memory of hybrid disks add one more task to Windows. Even worse, Windows already use several cache systems to optimize disk susb-systems. They all rely on the DRAM central memory of your PC; They are able to adapt to the size of the memory, to the user behaviour, to the list of active tasks/programs. But here, without even removing any of that feature (which is easily forgotten because it is nicely embedded) another layer is added.
Seriously, rather than buying a hybrid disk drive with all its added costs, I recommend that you go and invest into some more central PC memory. A little more SDRAM is what has the best impact on your PC performance (including the visible performance of the hard disk drive).
Last minute: Now, disk manufacturers are willing to explain that this is not because of thechnology that the hybrid disks are not more common. It’s merely that Flash memory prices are too high (!) and you should put more than the ususal 256MB usually found nowadays in hybrid models currently on the shelves [1].