But these days, most computing under Unix and Linux is done in a highly graphical environment, based on MIT’s solid and well-seasoned X Windowing System. In fact, it’s not uncommon to find users of such systems spending their entire working life using environments such as KDE or Gnome, which provide a highly user-friendly desktop, complete with drag-and-drop, pop-up windows and the other nice things one has come to expect of a modern computing environment.

Under commercial systems such as Solaris, the X environment is provided by commercial software that usually ships with the operating system.

However, Linux being largely free in nature, is a special case. Linux (and other free-Unix environments such as FreeBSD) developers cannot purchase X licenses for their chosen environment. (computersathome.com/nov99/novissue.html)

This led to the XFree86 project—a port of the X Consortium’s standard X platform to Linux, but completely free.

X consists of two components—an X server, and X clients. Contrary to what one would expect, X servers are actually installed on the client platr.Because of the free nature of the XFree86 project, developers are usually hampered by the fact that many graphics card manufacturers don’t wish to reveal their source codes. While X servers for most graphics cards do exist in the XFRee86 environment, they’re usually "clean-room" ports, not based on source code provided by the manufacturer. This typically leads to some inefficiencies that can slow things down. (It should be noted, however, that most XFree86 drivers perform as fast as, if not faster than, their equivalents under environments such as Windows).

Usually, this isn’t a problem, because for most applications, the speed of the XFree86 X servers is more than sufficient. But for applications like CAD, or some games, the performance of the free X servers can be a show-stopper.

This is where Accelerated-X from Xi Graphics steps in.

Accelerated-X is a set of drop-in replacement X servers for many platforms (including many commercial ones such as Solaris) that isn’t hampered by the unwillingness of developers to sign a nondisclosure agreement (NDA) that many graphics cards manufacturers insist on before they provide detailed documentation and even source code for driver development.

Xi Graphics obviously knows its business. We installed their two Accelerated-X suites (one for desktop usage and one targeted at notebooks) on a variety of platforms, ranging from low-end PCs, through high-end CAD stations and low-and high-end notebooks. In each case, the performance difference was startling.

For example, on my IBM Thinkpad 770 notebook, the standard X benchmarks showed a difference of nearly 20 times to the performance of the equivalent XFree86 driver! (This was using XFRee86 3.3.3.1. A subsequent release of version 3.3.5 added hardware acceleration to the driver for this chipset, reducing the gap in performance to about 15 percent).