Upgrade to CUDA ?

Hi all,

I’m working on a DirectX9 application in C# with SlimDX Framework, that makes real-time rendering with a lot of calls to shaders. I also use PhysX.
After reading some documentation on this technology, I’m wonder if I can use CUDA to improve my framerate ? And how I can use it ?
Should I change my engine to C/C++ ?
Should I replace SlimDX and use DirectX Compute ?
Doing this automatically optimize my rendering with CUDA, and also PhysX ?

Thank you for your time and explanation,
nyoshi.