Question: Seagate has released a product called the Momentus XT Solid State Hybrid Drive. This looks exactly like what Windows ReadyBoost attempts to do with software at the OS level: Pairing the benefits of a large hard drive together with the performance of solid-state flash memory.
Does the Momentus XT out-perform a similar ad-hoc pairing of a decent hard drive with similar flash memory storage under Windows ReadyBoost?
Other than the obvious “a hardware implementation ought to be faster than a software implementation”, why would ReadyBoost not be able to perform as well as such a hybrid device?
Answer: One major difference is that ReadyBoost is limited to USB 2.0 bandwidth (unless your computer has the ultra-rare and extremely bleeding edge USB 3.0), whereas the hard drive is on the much, much faster SATA interface.
Thus, putting fast flash memory on SATA alone is enough of a win to say definitively that it will be faster.
ReadyBoost is also designed around relatively slow I/O constraints, which limits the scope of what it can do, too.
The one review I found was quite positive. It does seem like, with the right algorithms, you could have the best of both worlds here — the speed of a SSD (mostly) and the capacity and low price-per megabyte of a traditional HDD.