Here are a couple of screenshots (click the image to get full size) of the GUI running on the Mac. It looks and runs just the same on Linux.
I am using an Edirol FA-66 Firewire for the sound card on the Mac. At the time it was running at 96000.
The first image includes the memory utilization from the Activity Monitor, which shows there is still 1.28GB available (the machine has 2GB) even with the Java GUI (radio.Radio) running, 2 copies of sdr-core (DttSP) one for RX and one for TX, jackd, sdr1000 (the sdr1000 hardware interface). On top of all this the Java GUI was run from Netbeans which is used as the IDE for development.
The second image includes the cpu utilization from the Activity Monitor, which shows we are running 70% idle.