Hello and merry Christmas

I have an problem with OPENGL and classes.
In my program I’ve created an ball class which bounce nicely around the screen, as you can see from my code im not using any processor demanding calculations, but still im only able to run 500 objects at a decent speed.
I’ve used OPENGL before and classes to run 10’000 objects without problems.
Any suggestions.

System:
Win 2K. ATI 9000, P5-115.

Kind regards
Mads Ny


//*************** code
import processing.opengl.*;

int antal = 2000;
ballClass[] ball;

void setup(){
 size(400,400, OPENGL);
 framerate(30);
 // SETUP BALLS
 ball = new ballClass[antal];
 for(int i=0; i<antal; i++){
   ball[i] = new ballClass();
 }
}

void draw(){
 background(255);
 for(int i=0; i<antal; i++){
   ball[i].update();
 }
}


class ballClass{
 float x,y; // position
 float speed=1.4; // speed of ball
 float vx=random(-1,1), vy=random(-1,1); // move vector
 float r = random(5,20); // radius of ball
 float tvx, tvy; // temp vector

 ballClass(){
   x = random(r,width-r);
   y = random(r,height-r);
 }

 void update(){
   tvx = vx*speed;
   tvy = vy*speed;
   collisionWithScreenWalls();
   // update Position    
   x += tvx;
   y += tvy;

   ellipseMode(CENTER);
   ellipse(x,y,r*2,r*2);
 }

 void collisionWithScreenWalls(){
   //X
   if(x+tvx+r>width || x+tvx<r){
     vx=vx*-1;
   }

   //Y
   if(y+tvy+r>height || y+tvy<r){
     vy=vy*-1;
   }    
 }
}
//******************** code off