Based on the same code than the particle painter (http://www.geeks3d.com/forums/index.php/topic,3625.0.html), here are some screenshots of a particle simulator. Around 200'000 particles + 8 attractors are processed by a compute shader (OpenGL 4.3).
(http://www.ozone3d.net/public/jegx/201406/glslhacker-particle-simulator-02.jpg)
(http://www.ozone3d.net/public/jegx/201406/glslhacker-particle-simulator-01.jpg)
1 million particles:
(http://www.ozone3d.net/public/jegx/201406/glslhacker-particle-simulator-03-1million-particles.jpg)