Patch 2.0 is a nightmare for video cards. Whatever was changed from 1.x to 2.0 taxes the GPU. In addition to this, patching 1.x to 2.0 turned off the "Framerate Stabilizer" and "Auto-Framerate Stabilizer" options under the "Trouble Shooting" section of the Video Options. Try turning them back on. I also recommend turning on the "Reduce CPU/GPU Usage" option. This wasn't on in 1.x but I need it in 2.0 to help control GPU temps.
Re-enabling the two options that got turned off after patching to 2.0 and turning on the reduce usage option solved my NVidia problems.