2.5 gig RAM--and no, I'm not confusing RAM with GHZ 
And yes, as you suggest, even the mighty G5 is EASILY crippled by less RAM. I've done many in-store tests on them and the typically low RAM they keep on most of them (ususally an absurd 512) really kills it. Ususally there's at least one machine with a couple GIG in the stores though, so I've been able to get a pretty good idea of how fast they are and compare it to my needs.
And yes, as you suggest, even the mighty G5 is EASILY crippled by less RAM. I've done many in-store tests on them and the typically low RAM they keep on most of them (ususally an absurd 512) really kills it. Ususally there's at least one machine with a couple GIG in the stores though, so I've been able to get a pretty good idea of how fast they are and compare it to my needs.