Hans-Jürgen Rauscher, System Architect at Wind River, compares the real-time capabilities of Linux and a real-time operating system.
Linux has become well-established in the world of embedded design, but there are often reservations about its real-time performance. There are significant advantages to using Linux. A careful analysis of the real-time performance requirements of a system design can reveal whether Linux can be used or a real-time operating system is necessary.
http://www.linuxlinks.com/portal/news/article.php?story=20080806142339199