It is possible to find out which was the last version of SL that included XGL by looking at the package list for each release (see the Press Releases section of the SL Forum). Anyway, it was 3.4f, which is now obsolete. If you're using an AMD ATI GPU, the newer fglrx drivers support AIGLX (I'm not even sure they would work with XGL?).
Can you elaborate, houkouonchi? What is the ATI GPU in your PC and how precisely is the performance poor? What behaviour do you see on screen when you are using AIGLX? Also, which versions of the packages xorg-server, xorg-x11 and ati-drivers (the fglrx driver) do you have installed on your PC?
HAHAH WOW I don't know how I did that. I think it was probably because I posted that right after I got off a 10-hour on call shift from work. That line should have read:
I have never ran ATI cards due to they have sucked on linux for a long time and I have been running linux for 8+ years back when their drivers were non-existent.
I have never ran nvidia cards due to they have sucked on linux for a long time and I have been running linux for 8+ years back when their drivers were non-existent.
I think I was thinking of writing "I have always used nvidia cards. I have never ran ATI cards, etc..." and some how the sentences got merged.
I have been hard-core NVIDIA since the geforce 256 mainly due to cards not working well on linux (I used a voodoo 3 before that which worked decently well)
As far as poor performance when running 3.5 on my machine at work on a geforce 6600 GT @ 3840x2400 I would get around 30 FPS just sitting at the desk top and 15 FPS in cube mode. If I enabled indirect rendoring that jumped up to about 50-55 FPS on the desktop and 25-30 FPS in cube mode (nothing on the desktop). Using XGL on 3.3 on the same hardware I would get 170-190 FPS on a desktop with nothing running and 90-100 FPS in cube mode.
The difference is even more noticeable when i have a lot of windows open which is why AIGLX isn't really feasible due to performance reasons.
Also simply running gkrellm when using 3.5/AIGLX X would consume 20-25% CPU usage vs the 0-1% CPU usage on XGL. In general AIGLX fealt much more laggier/slow.