XonX

I current have the NON-threaded version of xfree86 installed via fink on 10.2.3. What is the difference between it and the threqaded version? Should I run the threaded version? Benefits? Negatives? TIA! --Corey

The threaded version can be faster, particularly on dual-CPU machines, but there are some applications (notably Matlab) that dont' work with it. I'd suggest waiting for XFree86 4.3, which will be threaded, and install that - it should be here RSN.

Disclaimer: I haven't looked at the X11R6 code in quite a while, so I don't know much about this specific case. But generally...

Threaded applications are only faster on multiple-CPU machines, and only at the times more than one thread is running. On single-CPU machines, threaded applications are slower, unless you have some big overhead in your code (which is a design problem).
They also use more memory, but with today's ram size that's not generally a problem unless you run a lot of threads (on OS X each extra thread takes up about half a meg virtual memory by default). But ofc, when running many applications more memory equals more swapping.