(Nov 11, 2010 07:29 PM)mattz Wrote:  No "magic bullet", but if I were in your shoes, I'd do some simple detective work to see where the problem is coming from...

1) If your render function is reduced to only glClear(), are you still getting only 15 FPS? If so, you almost certainly have a timing bug or some logic error in the way you've organized your render cycle.

2) If you don't draw anything at all but run all of the state management/shader setup/vertex buffer code is the FPS still just 15? If so, it might be that you are doing some extraordinarily expensive non-drawing operations.

3) If you disable the shaders but draw all the geometry, does the FPS increase? If so, the problem could be a shader executing too slowly. I don't know about the iPad, but on some graphics cards exceeding some hardware limits makes your shader run in software, which absolutely kills performance.

4) If you keep all of your shaders and state changes, but draw just one object per category/shader/state, does the FPS increase? If so, you're probably fillrate or geometry bound, and further tests can tell you where the problem is.

Best of luck!

Thanks for the suggestions. To answer your points:

1) It goes up to 60.
2) I think it went up, will double check
3) We've not actually tried that. Will do so in a bit, thanks.
4) We went down to just the first triangle. Little change

I really don't think its fill rate. We took a lot of time to ensure that the ground mesh looks pretty much like a single extrusion. The tanks and stuff over the top aren't massive but lets face it its not like I can take them out.

@Jake: Hmmm, I think so but I'll double-check that also. We claimed to be decent at GL but our mac and iPad SDK experience is still fairly light - we could be making any number of mistakes like this tbh. Any other more global things you can think of?

Thanks fellaz. Good stuff so far...