It's a sad sad blog

So you installed the latest Ubuntu, enabled the 3D effects you've been seeing on YouTube and find that it runs dog slow on your PC. It appears the default install has some swapping settings that have a negative effect on desktop performance, luckily they are easily solved.

sysctl -w vm.swappiness=10

This should speed things up for you (you could even set it to zero if you like), keep the change permanent by adding it to '/etc/sysctl.conf'.