That might be the reason, most of us have 8 gb ram and still have the issue , while my assomate have 16 gb and is ok.
So is a issue of ram cosumption , and when the system see the Ram memory full , start a process called '' paging ''( or swapping ) that consist into use a part of the Hard disk as a ram memory.
But the Hdd is not fast like the ram , so to try keep up with the ram speed it runs at max , but this cause heavy lag
@SaucyFC