Issues, Workarounds & Localization

I have an odd issue with my 120hz monitors. When I run at 60hz I can max all settings and run EVE smooth as silk. When I run at 120hz FPS is horrid, except when I set Post Processing to None then it seems to run fine. I capped some video and some screenshots between the different settings, I really don't notice a visual difference when turning Post Processing to none or high, however, there is an obvious difference when running my monitor at 120hz as opposed to 60hz simply because of how smooth the transitions are in movement at the higher refresh rate. Anyway, I'm running two GTX 470's independently to drive two separate monitors. Anyone else have this issue? I sort of understand what Post Processing does, however, I'm not sure if the performance hit is solely resolution based, or a combination of the resolution and refresh rate. Also, one thing to note, I never capped while in space to notice visual differences, however, performance out of station was the same as in station when it came to setting the refresh rate to 120hz and leaving post processing on.