Re: Exhaustive memory test for Macs?
According to yesterday's Tidbits, the utility below will advise whether your installed memory will pass muster with new firmware updates from Apple (which have apparently refused to recognise some DIMMs):
Probably this is just some packaged, G4-centric vendor checklist, rather than the generic RAM-thrasher you envisage, but it's a tiny download and might be worth a look if you can boot to macos 9.1 on your machine.
Sorry I can't offer a more informed opinion. It didn't run at all on my iMac.