[ger21]

The only reason to get the 340 vs the 320, is if your controller can't send steps fast enough to the 320. Figure out how fast your servos need to spin, and then figure out how many steps you need to spin that fast based on the encoders you're using. If you can get that many steps from your controller, get the 320. Mach2 on a fast computer can send 45,000 steps/second. DeskCNC can send 125,000, I believe. It depends on your encoders and control software.