Timer Discrepancies

Question

I was working with a animation engine when I noticed a strange anomaly with the javax.swing.Timer component. What I did was have a "render" method that would draw ahead as many buffers as I initialized the bufferstrategy to contain. Then, using an actionlistener listening for the Timer events, I would call the getBufferStrategy().show() to flip in the next buffer. I created the timer as follows TImer tAnimator = new Timer(25, renderingObject) which would assumably cause the screen to redraw at a rate of 40 fps. However, my fps counter was showing that the screen was only being redrawn at a rate of 25 or 26 fps. ( The fps counter is simply an action listener on a different timer that fires once a second with a counter that is incremented every time the bufferstrategy gets flipped ) So I did a little nosing around and found that if I just made a simple Timer with an ActionListener that simply increments and print out the count every 1 second, the counter alone was only incremented 25 or 26 times.. similarly I experienced that very same anomaly with Thread.sleep(25,0); Instead of executing 40 times a second.. it only executes 25 or 26 times a second. Yet... if I run it full open, i.e. Thread.sleep(0,0) it executes 2.6 million times a second. Here's the code that I experience this with.
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.Timer;
public class TestTimer implements ActionListener {
     Timer myTimer;
     int nTicks;
     public TestTimer() {
          nTicks = 0;
     public void increment() {
          nTicks++;
     public void actionPerformed( ActionEvent e ) {
          System.out.println( nTicks );
          nTicks = 0;
     public static void main( String[] args ) {
          TestTimer test = new TestTimer();
          Timer aTimer = new Timer( 1000, test );
          aTimer.start();
          while(true) {
               test.increment();
               try {
                    Thread.sleep(25,0);
               } catch (InterruptedException e ) {
Any ideas as to why this happens and why I can't get a better timing resolution, so to speak?

Answer 1

Yeah, I was afraid that it was related to OS/hardware capabilities, I've found though, that I can get much more predictable results by running something like the following:
long nStart = System.currentTimeMillis();
while(true) {
     if( System.currentTimeMillis() - nStart >= 25 ) {
          drawFrame.render();
          nStart = System.currentTimeMillis();
     try {
          Thread.sleep(0);
     }catch (InterruptedException e ) {
That gives me a steady rate of 40fps which was what I initially wanted, just had to go about it in a different way. Thanks for the input though.