...i found a short article about recommended RAM sizes for gaming machines:
It's hard to determine the impact that RAM capacity has on gaming because of all the factors at play. Before we get into the results, we'd just like to discuss a few challenges we faced when testing system memory capacity.
The graphics card you use can influence how much memory you'll need for smooth gameplay, the speed of your storage can also impact performance.
The first and possibly the biggest challenge is picking the right hardware to test RAM capacity. The graphics card you use can influence how much memory you'll need for smooth gameplay, the speed of your storage can also impact performance.
For example, a GTX 1060 3GB will often see higher system memory usage than a 6GB model because when the former runs out of VRAM it uses system memory. If you run out of system memory, some game assets are moved to the local storage device, which is hopefully an SSD, and depending on how fast that drive is and how heavily it's hit with data, you may or may not see a noticeable dip in framerate.
So, testing with a GTX 1080 Ti and its 11GB VRAM buffer along with a super snappy NVMe SSD probably isn't the best way to determine how much system memory your average gamer requires. We'd also assume that if you have a $700 graphics card and a primary storage device of a similar value, buying 16GB or more of RAM isn't really an issue.