First, you'll want to remove or alter the cap.

1.  frameRate(24);

Use OpenGL...

You probably don't need smooth with OpenGL, since it already does full screen antialias (can't recall if it's 2x or 4x by default).

If you really want to see it scream, then unlock the frame sync to refresh rate.  I got over 400fps with this code.

1. //Original Code from :
2. //http://www.openprocessing.org/visuals/?visualID=38104
3. //////////////
4. //////////////Variable//////////////
5. //Sprites Maker Variables
6. int framenumber = 45;//Total frame number in the source animation
7. int SZ = 150; //Original sprite size (Have to be Square)
8. PImage spriteSheet;// the animation on 1 picture
9. PImage sprite[];//the animation in "framenumber" pictures
10. int sheetresolutionX=9;//
11. int sheetresolutionY=5;//
12. //System Variables
13. float speed=1; // sprites speed
14. float speedvar=speed*.2; //sprites speed variation
15. int amount=50;// sprite number
16. float repuls = 5; // repulsion effect
17. character ch[];
18. PFont font;
19. import processing.opengl.PGraphicsOpenGL;
20. import javax.media.opengl.GL;
21. PGraphicsOpenGL pgl;
22. GL gl;
23. //////////////
24. //////////////Setup//////////////
25. //Main
26. void setup() {
27.   size(640, 320, OPENGL);
28.   //smooth();//Make Fps drop.
29.   pgl = (PGraphicsOpenGL) g;
30.   gl = pgl.gl;
31.   frameRate(2000);
32.   gl.setSwapInterval(0);
33.   imageMode(CENTER);// center pivot
34.   font = createFont("Arial Bold", 50);//import font
35.   //setup character objects
36.   ch = new character[amount];
37.   for (int i = 0; i < amount; i++)
38.     ch[i] = new character();
39.   //Import Sprite sequence
40.   spriteSheet = loadImage("Sheet.png"); //Sheet file name.
41.   //divide sheet into frames
42.   sprite = new PImage[45];
43.   int cnt = 0;
44.   for (int y = 0; y < sheetresolutionY; y++)
45.     for (int x = 0; x < sheetresolutionX; x++)
46.       sprite[cnt++] = spriteSheet.get(x*SZ, y*SZ, SZ, SZ);
47. }
48. //////////////
49. //////////////Draw//////////////
50. void draw() {
51.   background(16, 103, 143);
52.   for (int i = 0; i < amount; i++)
53.     ch[i].check();
54.   // Display Fps
55.   fill(200);
56.   text(int(frameRate)+"fps", width-40, height-10);
57.   //if (key == 's' || key == 'S') saveFrame("blobbysprite_##.png");//saveframe
58. }
59. //////////////
60. //////////////CLASS//////////////
61. class character {
62.   PVector pos, dir;
63.   int frame;
64.   float spd;
65.   character() {
66.     pos = new PVector(int(random(width)), int(random(height)));
67.     dir = new PVector(random(2), random(2));
68.     frame = int(random(framenumber));//random do an offet on  each animation
69.     spd = random(speedvar) + speed;
70.   }
71.   void check() {
72.     //check other characters
73.     for (int i=0; i<amount; i++)
74.       if (ch[i] != this)
75.         if (pos.dist(ch[i].pos) < repuls) {
76.           PVector dir2 = PVector.sub(pos, ch[i].pos);
77.           dir2.normalize();
78.           dir2.mult(spd);
79.           dir2.div(8);
80.           dir.add(dir2);
81.         }
82.     //check mouse
83.     PVector m = new PVector(mouseX, mouseY);
84.     if (pos.dist(m) > repuls) {
85.       PVector dir2 = PVector.sub(m, pos);
86.       dir2.normalize();
87.       dir2.mult(spd);
88.       dir2.div(repuls);
89.       dir.add(dir2);
90.     }
91.     //draw character
92.     dir.normalize();
93.     dir.mult(spd*3);
94.     pos.add(dir);
95.     if (frame >= framenumber) frame = 0; //create the loop
96.     pushMatrix();
97.     translate(pos.x, pos.y);
98.     rotate(atan2(dir.y, dir.x) + HALF_PI);
99.     image(sprite[frame++], 0, 0);
100.     popMatrix();
101.   }
102. }
103. //////////////

Wahouu.