DRAM takes data from the hard drive, including data for programs and games, and it holds the data whilst people use those programs or games. This is because RAM memory is so much faster than a standard hard drive, or even an SSD. The data the RAM holds onto is then fed to the CPU and GPU for further processing and management.
With that reasoning, it would make sense that more DRAM would mean better performance, but the end result isn’t so crystal clear. What I've tried to figure this out is to add my DRAM up to 64Gb and see how it goes. The result is definitely positive encouraging: I finally can turn settings up to highest level and the SIMs run smoothly without a glitch
DRAM is not something that improves performance, however, if you lack of DRAM, your computer is going to use your hard drive as a RAM, which is not good for it and makes things slower. If your computer is using all its RAM, you may wanna increase the slots capacity?
DRAM quality and speed will be very important if you use a Ryzen CPU. And I suggest AT LEAST 16Gb. If you use an Intel CPU it is more important the quantity than the quality.