I'm using Reaper for about a year now, and I really like it. I've switched to Mac about a month ago, because I've got fed up with Windows reinstalling every half year and such things (I'm not trying to start a flame here

). My problem is that Reaper is running slowly on my Mac (dual 1 GHz G4 MDD with Radeon 9000Pro and 2 gigs of ram). I have a P3 900Mhz PC with integrated video (Intel 815 maybe) and 512 MB ram at my workplace, and sometimes I'm mixing on that machine, when there is nothing to do during my .
Reaper is running much more smoother on this P3 than on my Mac. I think the problem is not with the processor speed (playing back the same project while monitoring the CPU load), but with the graphics card. This is obvious when I'm scrolling the timeline, or zooming in and out.
I don't really understand why, because the Radeon 9000 is much more powerful than the Intel815, so I don't get it. Maybe I have to do some tweaking in the OSX preferences, or in Reaper preferences? Can Somebody give me tips on doing this (I'm unexperienced in fine-tuning OSX)?
I've tried out Logic, and it is running fine, but I cannot get used to it's interface and workflow (complete opposite of JoeJackson

). So if Logic can run fine on my Mac, I think it should be able to run Reaper fine too.
One thing that I miss in reaper is the ability to export midi tracks with tempo and time signature information. It would be much more easier to move projects between daws, because you could export a midi track as a tempo track, and then you don't have to manually edit tempo and time signature changes in the other daw.