The basic question we are asking is if it is better to use a dual processor to close the servo loop or use the computer's CPU. Using the motion card hardware method has been the industry standard for many years and known to be proven with over 200,000 motion cards shipped to date. Off loading the closing of the servo loop to a dual processor provides reliable servo update times up to within 62.5 microseconds resulting in cutting feedrate velocities of up to 122,000 IPM which is far greater than today's servo motor technology. Dual processors allow multiple events and multiple positioning motions to happen simultaneously. Closing the servo loop has to be a very tight algorithm and consumes a great deal of CPU time cycles. One could imagine how the main computer's CPU could keep up with all the other tasks it is asked to perform. The greater number of axes driven, digital I/O points to process and operator interface displays to be updated, makes one wonder at what risk does safety and reliability degrade to when the main CPU gets busy. For example, when using a dual processor, 3D profiles can be cutting at the same time a tool change is taking place or a servo motor positions a rotary table. The extra processor on the motion card is not only the best way to close the servo loop with the motors, it is also the fastest method known to date to produce the fastest block-to-block cutting speeds. Since a single computer CPU is already doing so much processing while reacting to digital I/O events, user interactions, graphic and position display updates, G code processing, ball screw error compensation, tool compensation, in-position and on-target checking, it is common sense that it would be better to have another processor to handle the tight closing of the servo loop with the motors. We all have to admit to the extra safety a dual processor offers if the computer pauses, fails or locks up. Every PC-based controller that wants to control a servo motor needs a motion card to work with the computer of some sort, bar none -- be it a non-intelligent digital-to-analog card without a dual processor to a full DSP-based intelligent motion card with a dual processor that will close the servo loop automatically and independently of the computer's CPU. When it comes to all the hardware devices needed, such as analog to digital converters, digital encoder readers, analog inputs and digital I/O, we say that it is far better to purchase one card from one manufacturer than to buy several cards from different companies. The computer's CPU was never designed to close such an intensive task as a servo loop and still process other events. There are a dozen major motion card manufacturers in the United States with hundreds of professional installers and resellers for these motion cards in every state in America. Therefore, propriety hardware is not an issue.