I have problems that games on my laptop(CS:GO) take a very long time to load and don't run smoothly, although it used to run smoothly on windows os. (I have converted to ubuntu just a week ago!!)
After some research, I found out that this may be caused by swappiness value. I tried playing around with values on my own but that made it even worse.
By the way, I only have 4GB of RAM and I have set my swap file to 4GB as well.