Does anyone else running Borderlands 2 on an AMD iMac play with PhysX enabled? I've got it on my Windows 7 Bootcamp and get fairly decent FPS on my i7 2011 iMac with the 6970M (1GB). Apparently the CPU has to deal with the PhysX effects, as they are a NVidia proprietary tech and the AMD card won't touch it. My question is, do you ever get heavy slowdown when water pipes are used in a level? I've only found it in 3 places, most recently in the Bloodshot Stronghold, but it makes the game unplayable when running in to these areas. Any way around this? The game looks great with the effect on, so I want to keep it that way, but would love to run a couple of tweaks to bump up the performance, like just removing the leaking pipes effect... Anyone tinkered with this?