Possible solution for graphics slowdown on Nvidia;
Manually set the file Pinballarcade11.exe to use Nvidia graphics instead of integrated graphics. This is done in Nvidia 3D settings.
I had to do this for my laptop with Nvidia 840m Graphics, otherwise TPA used the Intel 4400 graphics resulting in very poor performance.
And THANKS Mike and Farsight for TPA with DirectX 11
Would there be something equivalent to this for for the AMD Radeon graphics cards? Just having another option to try and narrow it down would be nice (especially since I'm probably at least a month away from being able to save up for a new computer).