everything sluggish after amd driver installation

I went to Additional Drivers and installed the ATI/AMD proprietary FGLRX graphics driver, and upon restarting, well it just feels really sluggish. like the framerate took a nosedive. I tried uninstalling it but it didn't help. Am I missing something here? I'm new to this whole linux thing

edit: turns out the slowdown only happens when I have two displays connected. Any way to fix?