I have an old laptop with 4GB of ram. I use a basic Linux system monitor to check usage. In reality I have 3.7GB. Opening Inpervious, maybe watching a YouTube video on the browser, it has gone as high as 3.5GB. At that point the screen becomes unresponsive, the mouse freezes, etc. Keep in mind this isn't a completely accurate assessment, since I am running other background programs. All else being equal, Brave uses less RAM on my system. In fairness to Impervious, regular Firefox uses about the same and has much less functionality.