Global/Static function/variable slower to access?

Hey guys,

So I learned about the cpu and some real low level stuff recently and I have to ask, are global/static variables or functions slower to access/call?

The reasoning may be because that they are outside the current scope and would not be found in the registers or L1 cache and would probably located in the RAM.

I hope I am making some sense.

I think you would have to examine things on a case by case basis.

On systems where stack space is dynamically mapped, the first time you access a local variable may result in a page fault, which would be exceedingly slow.

Likewise, an often accessed global variable may be "permanently" in cache.

But then again, on a paged virtual desktop OS, the whole thing could be being paged in and out of memory anyway.

The difference is minute (and could go one way or the other). And being so small, it's effect will be swamped by all sorts of other factors, some under your control (like using the optimisation flags), and some not under your control (like how many other processes are running on the machine).