Kubuntu , Ubuntu (unity) : Which is faster?

Question

I installed Kubuntu package on top of Ubuntu server; It works alright but compared to the specs of the computer (i3,4GB RAM) I would expect more. The problem is not so much the speed of execution of applications but rather the smoothness of the UI. (KDE) (frame rate?) For example Chrome browser, Skype...

I don't know if this has to do strictly with how these applications were ported to Linux or with the system itself (I guess the first).

Thank you for any suggestions to improve performance and UI responsiveness.

(edit) Maybe tweaking the Nvidia-settings could have some effect.

Answer 1

According to this wikivs.com,

Gnome users typically accuse KDE of being bloated. Besides eating more memory, KDE desktop load times are slower because they have to load more from disk. KDE users justify this by saying that once the libraries are loaded, applications start quicker.