So Mountain Lion removed the toggle for smooth scrolling in System Preferences, General. I just found out today when I purchased a 13" rMPB and wanted to kill it so I could scroll lag-free with spacebar in Chrome. I googled the issue and found the following commands: defaults write -g NSScrollAnimationEnabled -bool NO defaults write -g NSScrollAnimationEnabled -bool false They worked, but only in Safari. I'm looking for someone who knows OSX better than I to help me figure this out. I know there has to be a way because I also bought a MacBook Air a few months ago with Lion on it and immediately unchecked smooth scrolling. After updating to Mountain Lion, the setting stuck and smooth scrolling is still disabled in Chrome exactly like in Safari, so the setting must be somewhere.