I just bought an Asus UX32VD ultrabook with 4GB ram 2 weeks ago. I don't have much software installed since I bought it, but its already starting to give me problems. The memory usage is extremely high already ~80% with just Google Chrome running. I have never encountered problems like this before and am admittedly clueless about how to fix this. I am currently using Windows 8.
Also, it might be worth mentioning that I went straight to downloading and installing all updates from Windows Update when I first started the laptop up. I don't recall it being slow prior to that, but then again I didn't have anything else running then.
Here is a screenshot of what the task manager says about the processes.
The same crappy high memory usage problem over and over again! Why don't you trust the windows memory controller? Since Vista it does a very good job and makes sure you will never run out of memory. Or have you ever seen the "out of memory" message lately?