Rendering 4000 Cubes

I'm looking to create a piece similar to http://directtovideo.wordpress.com/2010/03/05/vimeo/#comments. I'd like to render only about 12000 cubes. With rendering about 4000 cubes with a spot light the frame rate is about 7-8 FPS. I'd like to add more rendering effects and swarming behaviour, so it would be ideal to get what I have now to more acceptable framerate. Does anyone have any advice? I feel like instancing would be helpful but I don't think that's possible (I'd love to be proven wrong on this ;-)). [/url]

 

if you write code that merges the cubes into less meshes yes
otherwise no, as you have 1 drawcall per cube already pre light. with light it doubles if it is a pixel light