Kubuntu has fully matured and stabilized and comes with the brand new KDE Plasma workspaces and other KDE technologies. Like any other operating system Kubuntu also needs a little bit of work to get it ready for you. There are a few things which are optional and I have added them here based on my own usage, you may not need them.
#1. Install proprietary drivers
The first thing you need to do is install drivers if you are using proprietary GPU. Kubuntu comes with free drivers so it will work out of the box on a majority of machines, but if you need better and smoother performance than you may want to do it.
Hit Alt+F2 to fire Krunner and then type Additional Drivers.
Open the tool and it should show the drivers available for your GPU. Go ahead and activate it.
You will need to reboot your system in order for the driver to work.