are you using that framebuffer as a texture? or do you mean framebuffer as in render target?

You should only draw when you need to. for example, if nothing changes in your scene, there's no need to redraw everything. use dirty flags or something to know when something has changed

Without knowing more about your application, i can only say drawing to  your framebuffer every 5-10 frames is fine if you don't need to draw to it every frame

Also, make sure your profiling, sometimes the bottleneck is not where you think it is

I bet you are recreating some arraysbthat you constantly pass to gpu memory, without code we cant help

Did you try to draw directly to the backbuffer? 

What is the size of your framebuffer?

How complex is the shader that's using the texture attached to your framebuffer?

As what iedoc said, the bottleneck can be anywhere.