ongun I guess linux is not needing all that memory;
Linux uses less RAM than Windows because less is running in the background, typically, but it doesn't take much in the way of ordinary use to push memory usage up over the "minimum" most Linux distros recommend:
Distros still suggest that Linux can run acceptably on 2/4GB RAM and 20/30GB disk space. Technically, maybe. And maybe those requirements will work okay on a travel laptop used to access the internet for e-mail and browsing. But a modern computer user, running multiple apps and storing a reasonable amount of data, will quickly exceed the recommendations.
ongun Hopefully we will fill the memory one day
Why would you want that? When RAM is at or close to capacity, you start running on a swap drive, with performance loss and additional stress on the system. To my way of thinking, a good rule of thumb is to plan to work at about 40-60% capacity. If you typically use 3/4 GB RAM, install 8 GB; if you typically use 6/7/8 GB RAM, install 16 GB.
