Best steady framerate?

Hey all,

What would be the best way to accomplish the best steady framerate. I’m currently using setInterval, and I’m experiencing that the fps goes something like this:

Instead of a nice, steady, flow of continues 30 fps (what I am trying to achieve here).

What would be a better way and what do you use?

Thx,
ArmoredSandwich AKA ImWithNoob.