But the back-end performance is extremely slow and frustrating (the front-end is slow, but useable).
The hosting statistics shows that very rarely We're using above 2.5GB of ram, the average is 1.7GB.
What do you think causing that?
Also, to this system do you think it make sense to move to a 4GB setup, or 2GB with LiteSpeed should work better? (I don't know if LiteSpeed can lower the memory usage and provide better performance, It's a total noob question).