How do I disable visual effects in Ubuntu 12.04.1?

view story

http://askubuntu.com – So I finally managed to install Ubuntu 12.04.1 on my G5 iMac but I don't want any fancy visual effects. How do I disable those? My user logs in automatically and I can't find anything in System Settings, there is no visual effects tab inside the appearance applet. I would like to keep the nice Unity shell but just disable visual effects so that the Quartz part of my video card doesn't get used. Thanks! (HowTos)