function main() {
var i = 0;
double j;
while(!key_e) { wait(1); }
timer();
while(i < 999999) {
i++;
}
j = timer();
printf("Time: %f",j);
}

This returns a value of 3625 microseconds for me and means
3625 * 1/1000000 sec = 0,003625 sec.
Divide it by 999999 and you have the speed.