as phoronix tests show, Nvidia binary driver is much better than nouveau for all nvidia graphic cards. but i have a strange problem with nvidia binary driver in my laptop (hp pavilion dv2500 with NVIDIA Geforce 8400m GS card).

the problem is that my laptop works good with nouveau driver in ubuntu 12.04 with unity 2d; but when i activate nvidia binary driver to enhance the performance and to use unity 3d, the performance shrinks severely, in fact, performance of my laptop with nvidia driver is much weaker than nouveau. for example when i run "glxgears" command in ubuntu with nouveau driver, the resaults are almost between 320 to 420 but if i run same command when nvidia binary driver is activated, the resaults shrink severely and are almost between 50 to 63. i had this problem in both ubuntu and befor that in openSUSE. also i tried different versions of Nvidia binary drivers but the problem exist with all of them.

i tried to solve this problem wityh asking about it in ubuntu forums (here), openSUSE forums (here) and many other linux forums but unfortunately i find nothing useful.

So, here is my last chance to find what is the problem with my graphic card and how solve that. please help me.
thank you.