Not too long ago I switched from Windows 7 to Ubuntu 12.04 (64-bit) on my laptop, which only has a AMD Dual-Core E1-1200 APU 1.4 GHz processor but 4GB RAM, in the hopes that I would get more out of my weak CPU. I wonder if I could do anything further to get more out of my hardware, so I thought maybe I could switch to Xubuntu or Lubuntu. I know for example Lubuntu is much lighter on the RAM but since I have plenty of that (relatively speaking) is there a point to switching or is it a waste of time? If it is adviced for me to switch, to which version?
Also, is there a big difference in CPU intensity between 32-bit and 64-bit?
Since I am new to the world of Linux in general I'll take any advice I can get. Thanks a bunch!