I'm gonna take a couple of the most helpful excerpts from the old Speed Improvements to Leopard thread and put them here. All credit goes to Altemose, eyoungren, and Intell. All rights are reserved to them.
"You maybe able to boost your graphics performance a little bit more by enabling OpenGL. In my tests, graphical applications performed smoother and faster. To do this simply open a new Terminal session and enter this command.
Code:
sudo defaults write /Library/Preferences/com.apple.windowserver \QuartzGLEnabled -boolean YES
A way to speed up the Finder is to speed up the Finder's UI performance is to use OnyX to speed up the display of sheets. To do so, simply download and install the last version of OnyX for Leopard (2.0.6).
Open OnyX and go to the "Parameters" section and set the "Speed of Display of Sheets" to "Very Fast"."
"Just note that QuartzGL/Quartz 2D Extreme requires a CoreImage card. The GeForce 5200 is not able to properly run it as it is missing one of OpenGL/Quartz 2D Extreme's critical instruction sets."
"I just wanted to share a tip with you PowerPC enthusiasts. Apple and other OS manufacturers use a technology called V-Sync which essentially vertically refreshes the screen. It is mainly designed for CRT displays rather than LCDs, so we can safely disable it.
Anyone who has used Tiger knows how smooth the dock can be on opening applications, minimizing windows, and magnification. Unfortunately, many late PowerPC Macs like my PowerMac G5 and early Intel Macs are slowed by BeamSync (Apple's term for V-Sync). I am not sure of the root cause of the slowness, but it is rather disappointing to see choppy opening animations."
"If you have the Secrets pref pane installed, just search for Beamsync (it's in the System section) and turn it off there."
Thanks to personal experience and going over this thread, I have found that Onyx, Secrets, and ShadowKiller are most helpful applications when running Leopard. Like eyoungren raised, Onyx is helpful for disabling Spotlight, Dashboard, and Bonjour (I'm pretty sure), too. Secrets for disabling Beam Sync, and enabling OpenGL and Quartz Extreme 2D. And I believe turning off the menu bar transparency via System Preferences, launching ShadowKiller, disabling Beam Sync via Secrets, and enabling the 2D dock via Onyx, are also the most helpful tips especially when running Leopard on a G4 of any kind. Coupled with all the other findings of ours from this thread so far, of course.
EDIT: I actually wouldn't turn off Beam Sync, even if you're on an LCD. While browsing these forums on WebKit, there was a constant white flickering about the pages. So I turned off Quarts Extreme 2D, and OpenGL, no difference. I turn them back on again, set Beam Sync to 'Automatic', restart, and the flickering is now gone. All back to normal.
So I actually suggest just turning on OpenGL and Quartz Extreme 2D and leaving Beam Sync alone. I still have the updated graphical performance, and I still got the boot up time to be lessened even more by 8 seconds with Beam Sync on automatic, only now, no internet flickering. So my boot time is 40 seconds with Quartz Extreme 2D and OpenGL enabled. My machine's specs are in my signature.
