This article is from the MachTen & CodeBuilder FAQ, by Jaime Julca firstname.lastname@example.org with numerous contributions by others.
Tenon's X architecture is very different than the other X servers that are
traditional Macintosh applications. Tenon sends the output of the X commands
directly to the Macintosh hardware screen buffers instead of using
QuickDraw. This has profound performance implications. In addition, Tenon's
X uses the UNIX TCP sockets for communications instead of MacTCP; this
further improves performance.
Tenon's X is said to be the fastest on the Mac market. X11perf benchmarks on
a 25MHz 68040 Centris yield an XMark of 1.1 -- better than a SPARCStation 1!
On a 40MHz Quadra 840av, the X performance rivals a SPARCStation 2. XMark
ratings are not yet available for the native X performance on a Power Mac,
but Tenon's architectural advantage carries over to that platform as well.