That would be typical wood router territory? 5 million data points from a 3D map? I am not familiar with that class of program. I'll pass.some of my programs have hundreds of segments per inch.
Instead I tend to go for engineering designs, where a 50 mm circle can be machined with one or two lines of code.
This does raise a point about lines/second. My CNC can only machine a few lines/second, as each line is quite long. It is possible that the PC could limit the machine speed IF it went through the PP. I use an ESS, which can turn lines/second into lines/millisecond. Having an external engine for the pulsing is so very helpful for speed. Mach, UCCNC and LinuxCNC (and others too I imagine) can all do this today. Here's to FPGAs!
Cheers
Roger