太多的glDrawElements导致低fps？ OpenGL ES1.1（iPhone）

I am developing a 2D Tile based game and currently struggling with performance issue as I am getting around 10 - 15 FPS even when running on iPad 3. OpenGL ES Frame capture reveals that I am making call to glDrawElements 689 times per frame! Is that a lot? Could it be the case of low performance?I am developing a 2D Tile based game and curren