local or global performance

If a variable is local or global does that have an impact on the overall performance of an application ie speed, memory.

I know the difference between local and global within a program but as I need to keep tabs on several variables (the debug in blitz is shat) I output them on to the screen; i usually make them global but am thinking that i could make most of my variables global and not worry that i cant access them etc

It doesn't make any difference in terms of speed that you would notice.

Most of the time(read like 99.99%), the difference would be negligible, but I suppose in certain scenarios, globals might be faster.