How to create RAM drive?
Quote from http://www.omgubuntu.co.uk/2010/11/move-google-chrome-cache-to-ramdisk/:
gksu gedit /etc/fstab
Add the following line to the bottom of the text file that opens but BE CAREFUL – do not touch, edit or enter ANYTHING else:
tmpfs /media/ramdisk tmpfs defaults,noatime,mode=1777 0 0