It's no secret that the performance of a computer’s disk subsystem is quite an important factor when it comes to comfortable user experience. Of course, it cannot add more computing power to your CPU or increase the frame rate in your favorite game (if you've got enough of system memory), but having your OS or heavy applications like Adobe Photoshop load much faster is a very nice thing. A computer’s higher overall responsiveness is what we mean by comfortable user experience here.
The most straightforward way to make your disk subsystem faster is to buy a solid state drive large enough to store your OS and applications. However, this method is way too expensive for many users. It also involves the trouble of reinstalling your OS and applications on the SSD or moving them there from your hard disk.
A modern SSD with a capacity of 100 to 120 gigabytes and based on the cheaper MLC flash memory type can be bought for $200-270, which is about $50-100 more than the price of a 3-terabyte hard disk drive. This storage capacity will only be enough for installing an OS together with a standard selection of tools you use every day plus a few heavy professional applications. Everything beyond that limit will have to be stored on a traditional and slow HDD or you have to spend even more money to buy a larger SSD.
That said, the specific applications the user works with over a short period of time (a week, for example) is often rather limited. One week you're editing your summer vacation photos in Photoshop, playing a latest 3D shooter or browsing the Web, but the next week you're doing your work in Microsoft Office. So, some files would take place on your expensive SSD without you really needing them at the moment.
Is there a way to increase the efficiency of your fast SSD storage? Yes, of course. The solution is in storing all data on a conventional, cheap but high-capacity HDD and using a low-capacity not-very-expensive SSD as a cache for the files and applications you're frequently accessing right now.
This concept of a hybrid disk subsystem can be implemented with the Smart Response technology supported by the Intel Z68 chipset or with a special disk controller like HighPoint RocketHybrid 1220. Both suggest that you use a small-capacity SSD as a cache for a large-capacity HDD. There are no viable single-drive hybrid solutions as yet, i.e. an HDD with a large internal flash memory cache, so you have to use two drives instead of one.