It mostly depends on the visible tab. Rapid doesn't use OpenGL acceleration, so it's a pure software renderer. The multiband and voicing waveform display have to render quite a few samples (at 60fps). If you want to save some extra CPU you could also test with 30fps settings enabled (better restart after change) and test performance with the envelope tab visible. The complexity of the line drawings is a bit simpler there.
Interesting that you test the GPU performance first. I thought it's all about the DSP performance!?


