Why? Windows is a pre-emptive multi-tasking operating system and mouse handling is essentially independent of applications. Inserting sleeps will not speed anything up and there is no need for a yield as the OS already asynchronously handles mouse position.

That's fine if you don't expect the process to be able to print anything to a window.

You still don't make sense. Have you tried the OP's code? It works fine for me and (with a small tweak for counting) gives about 15,500 updates per second (not sure why the OP found that too slow actually).

use strict;
use warnings;
use Win32::GuiTest;

my $start = time;
my $times;

1 while time - 1 < $start;

while (time - 6 < $start) {
    my ($x, $y) = Win32::GuiTest::GetCursorPos();
    print "X is at $x, Y is at $y\n";
    ++$times;
}

print +($times / 5), "\n";
[download]

True laziness is hard work