[ger21]

I've never heard of block processing time being a bottleneck in Mach2. The only limitations I've seen are 45khz pulse rate. Per axis, I believe. Say your using 10x microstepping, this gives you 4500 Full steps per second. On a 200 step stepper, that will give you about 22.5 revolutions per second. If you need to go faster, Gecko should be releasing soon their G2002/G2003 which Mach2 can control, and can output 200,000+ steps/second.