Here’s another Vista feature worth knowing about.

To perform well, Vista requires 2Gb of system memory. That’s partially because Vista is more demanding than Windows XP but it’s also because we’re all running more programs simultaneously as the years go by. 2Gb of RAM is enough memory for solid performance for almost everyone. (Except gamers. They’re still in a separate category.)

Adding more memory can boost performance but frequently the difference is not spectacular. Vista has one more trick up its sleeve for extra performance, though, and it can be done cheaply and on the fly.

When you connect a USB drive to Vista, it asks if you want to use its empty space for “ReadyBoost.”

With permission it uses the unused space on the drive as a cache to speed up hard drive operations. New USB drives transfer data much more quickly than older ones. Vista tests the memory stick and uses it to speed up the computer if it passes the test.

Instead of acting like RAM, the USB drive acts like a very fast hard drive cache. If you keep a lot of programs running, you’ll likely notice a pretty dramatic difference as you move from one program to another or start operations that would normally require a lot of hard drive thrashing. There’s a copy of all cached data on the hard drive, so the USB drive can be removed without notice and nothing will be lost.

Here’s some information from Microsoft about ReadyBoost, and here’s a blog entry from the Vista team last year with more details.

I got a 4Gb Sandisk Cruzer at Costco for $49 and the difference was immediately noticeable. Programs are snapping into place very satisfyingly. I’ll probably leave the USB drive in place most of the time.