As you're just starting out with Rails, I wouldn't worry about performance issues. Get the basics down and then benchmark your app. If it's not performing adequately for your specifications, find the bottlenecks of your system, make changes, and benchmark again. Premature optimization at the best of times is a bad idea. As you're just starting out, it's likely going to cause you much more grief than any gains you might find.
grzm seespotcode net