you're not thick, you just don't know the answers yet!
i don't know, so maybe a gamer type will know more than me, but the 4 something X thing i can tell you about.
the X server is what enables programs to display graphical information onscreen. basically the X server is what allows a GUI to occur in *nix systems.
in linux for intel type machines, the free and open source X server is XFree86 and the current version is 4.2 (or maybe 4.3 now) however many linuces still come with XFree86 version 3.6 (i think, it's 3.something anyway) for in case the newest one won't work with your video card. my ATI Rage seems to work better with Xfree 3.x than Xfree 4.x, but when i turn off hardware acceleration (which is possibly something to do with the '3d' you mentioned, i am no expert but), it seems to work fine, but i really don't know if it would be good enough for games, and i only have a celeron 700 anyway, so i can't tell if it's the video card or the CPU that's slow.
that's all i can help you with, but i am sure somebody else will come along soon.
[ March 31, 2003: Message edited by: Calum: crusader for peace & freedom ]