Your question is rather subjective: "prove its performance"
The 2 key questions are:
1) How does your computer get the data?
2) How will you output the value to the motor?
Everything in between will somewhat depend on those answers. For example, if the data coming in is from a serial port (RS-232 device) then there are timing limitations due to the speed of RS-232. But if you are reading data from memory or from a hard drive, then speed is dependent on memory speed, etc.
What hardware are you using for your motor control? Any NI hardware?
In any case, a good rule of thumb is the K.I.S.S method. (Keep It Simple Stupid). For best performance of any vi, use the minimum amount of controls, indicators, and graphs on the front panel, and the minimum number of functions and structures inside the block diagram. Things that look really neat, but aren't vital to the purpose, will probably hinder performance.
When you have the smallest amount of code possible to perform all the necessary functions, then you have maximized performance. That being said, it is often desirable to make the user interface easy and fun to use. While this may slow down some performance, that may be fine as long as it still functions as needed. The eye candy (the colors, and the graphics, and the easy to use interface) are part of what makes LabVIEW so great.
Hope this helps. If you have a specific question for your program, you should post your code.
B-)
