Most projects won’t use more than 1GB of RAM. I personally have never used or even seen anyone use more than 2.5GB in an FL Studio project. They recommend having at least 4GB of RAM or more, not 8. The minimum requirements are listed here on Image Line’s official website. These same people will recommend that you have 8GB of RAM or more.
Many people will tell you that you need to upgrade your RAM. Well, one thing you should notice right away is the difference between the CPU usage (the red bar that says 100) and the RAM usage (251MB). Are you tired of hearing pops, clicks and static when you play your beat? Does your CPU usage bar look like this?