I have an HP 6715b with ATI X1250 graphics card. I am running Ubuntu 12.04 and I observe that Unity is running slowly. Is that normal?
My system configuration is: 4GB RAM and AMD Turion x2 1.9 GHz processor.
Open your terminal and type:
sudo apt-get install htop
After it gets installed, type
htop and see what process is consuming the most RAM and CPU. You have to observe it and judge whether it a necessary one or not.
If you find any process/application as behaving abnormally (by consuming more RAM, CPU) that is the cause of problem. Report the memory intensive process as a bug/problem.