First I took a standard USB 2.0 key (I’ll list the prerequisites shortly) and plugged it into my machine. I’m running Windows Vista Beta 2, Build 5346, but I’m told that this works with the latest CTP made available to beta and TAP members as well as MSDN Subscribers. Upon plugging the USB key into my computer, I was greeted with the standard "AutoPlay" dialog box asking how I wanted to the operating system to treat the USB key. However, with ReadyBoost I get the additional option (circled below in the screen capture) of using the key to "speed up my system".
Once I click the "Speed up my system" option, the Properties dialog box for the device is displayed where I can specify to start/stop ReadyBoost usage of the device and how much space I want used as a memory cache. (Actually, according to one of the Product Specialists here, this space is used more as a flash-based page file than true RAM, but the impact is that the more space you choose here, the more benefit you’ll get in terms of overall system performance.)
(In order to return to this dialog box, open the Computer window, right-click the drive (F: in this case) and select Properties. From there, click the Memory tab (as shown in the previous screen capture and adjust the settings as needed).
For the inquisitive, opening the drive in an Explorer window reveals that ReadyBoost has created a cache file of the specified size.
If you have a USB key configured to use ReadyBoost and then insert a second key, Windows Vista will display the Properties dialog box where you’ll see the message on the Memory tab as shown in the following screen capture.
While ReadyBoost will work with other devices – such as SD Card, CompactFlash, etc. – I’ve only used it with a USB key and here are the baseline requirements the team gave me regarding what ReadyBoost will work with:
Update: Due to so many questions about this feature, I've tracked down the Program Manager (owner) of this feature - Matt Ayers. Matt has put together a complete ReadyBoost FAQ for everyone that I've posted in a separate blog entry.
Therefore, feel free to make comments here, but if you have any questions, first check out the FAQ and if it's not answered there, post me a question and I'll see if Matt can update the FAQ with your question/answer.