THIS MY BE A SIMPLE QUestion.

lets say i have a loop like the one below. how long would it take for x=65,000. i have a 4 mhz proccessor (actually 4.19 i use HS)

x=0

loop:
x = x+1
goto loop

basiically i need a have a variable count for 500 ms. how high would it have to count? am i goning to need to nest a counter? is it 1 assembly instruction for every clock cycle?