No, people just forget. Once you've been running a 500MHz machine on
broadband for a year you forget what it was like to upgrade your system
on a 100MHz machine with a dial-up connection and a monitor that only
does 800x600 resolution. Rosegarden4 and Ardour will run on those bigger
machines, but you're going to be better off running Fluxbox, Openbox or
fvwm. Using an external MIDI sound source rather than softsynths will
help too. There are lots of ways round the limitations once you have the
software and _some_ hardware to play with.