Quote Originally Posted by BobEdge View Post
Can anyone tell me how to work out how long an instruction takes to execute when running at 20MHz?
That would be about 5,000,000 single word instructions per second. But those are assembly instructions, not PicBasic instructions. Each PicBasic instruction differs in length. To get an idea how large parts of your code is in assembly, try the codesize.php utility here: http://www.picbasic.co.uk/forum/showthread.php?t=2418

Then you can try to figure out the approximate speed of parts of your program.