Hello I have an old bench computer running mach 3 and smooth stepper. I use this to cut small 3d models it would save me lots of time if I could load up the whole bed and cut at once however my computer (2.4ghz 3 gig ram) times out the smooth stepper if it get more than 3 boards at a time or if I click on the simulation window. What is the best machine I can get to fix this? I understand there is a  memory limit due to OS.

Try turning off the toolpath display in Mach3 and see if the problem goes away.