If you compare a 64bit Linux distribution with a 32bit system on the same CPU, there are marked differences in speed. In particular, those programs and system functions that access the kernel directly, profit from the kernel optimised for 64bit, for example the Gcc compiler, which can – depending on the version – run up to 50 percent faster.

Apart from Gcc, all 64bit distributions include a range of system functions and utilities which are optimised for 64bit operation, including the basic libraries, compression commands, GUIs and system commands. Applications that require intensive processing, such as databases or 3D rendering software –MySQL and Oracle 9i or Pov-Ray, for example – profit from the optimised system environment, as do programs with a high proportion of floating-point operations. Cad applications are also speeded up. The improvement in performance achieved by the Gimp graphics suite is sensational, especially in combination with the 64bit version of Image Magick. Here, performance can be increased by up to 100 per cent. When encoding audio files into Ogg or mp3 format, performance can increase by over 50 per cent.

Although it might appear that video editing is one area certain to get a boost in performance, because many of the important standard multimedia libraries such as Ogg-Vorbis, Directfb, XMMS and Xine have already been ported to 64bit, the reality is different. Even if the video codecs are available in 64bit packages, they have not usually been specifically optimised for 64bit CPUs. As a comparison, the excellent performance delivered by the codecs in theWindows encoding package Virtual Dub are only possible because they are written in assembler code and can therefore make full use of the CPU’s capabilities. The compatibility of 64bit Linux and 32bit software has not been neglected: the older 32bit libraries remain in the system directory Mb. Those libraries that have been ported to 64bit are stored in separate directories.