The_Editor have a good point; don't mix SDRAM modules and you won't have problems.
1. There's absolutely _no reason_ whatsoever to use 512MB in combination with AOS4. It (AOS4) will probably not grab more than 10% after boot (unlike WinDoze 75%).
Win: 512=128
AOS: 512=500 (disclaimer: rough estimation)
:-)
2. In some specific cases the G4 (running G4 comiled code) is extremely fast. And I don't mean "just" twice as fast. In all other cases G4=G3. So the G4 is not overall faster, which makes it very difficult to attach a figure to it. The G4 should also have a faster FSB (allowing G4>G3), but don't quote me on that; it's not certain the mobo will allow use of the faster FSB speed.
3.Search Tom's Hardware (
www.tomshardware.com) for performance comparizing, check with dealers which models are actually usable with AOS4.
5. Hahahahahahahahahaharrgh! ...Muhahahahaha! _cramps_ arggh! Gasp! Hahahaha!
Google laughing filter:
Linux is only to be installed with help from experienced users. Any first-use attemts to install is futile. Unless you're booting from a cd-image that is. Especially when we're talking installing applications when using PPC hardware since you most probably will have to compile the sources yourself.