I have dual boot Ubuntu and Windows on my Lenovo Yoga 2 Pro (RAM 4GB, SSD 120GB, Intel® Core™ i5-4200U CPU @ 1.60GHz × 4 ).
Ubuntu is freezing time to time. When I look at the System Monitor my RAM is almost all eaten up (~95%) and lags are understandable at that point, but on Windows even more programs did not cause such lags.
When I boot into Ubuntu, almost half of the RAM is eaten up already. I first thought that it was Disk Cache, but I have read that it gives up its memory portion for other programs to run. However, in my case, the 4GB is eaten up very fast.
I have swap of size 2GB on my SSD.
How can I stop lags?