RAM will affect FPS and you are going to want at least 16 GB in order to maximize your FPS without overspending. It is more than just the amount of RAM that affects FPS, if you want the best performance you should dual-channel your RAM.
Is CAS latency 18 bad?
Cas latency doesn't matter as much as the ram frequency does. For ryzen 3000, 3200mhz or 3600 mhz with cl16-cl18 will be fine. CL18 by itself doesn't mean anything, you need the RAM speed number too in order to calculate the actual latency.
Is a CAS latency of 16 good?
The lower the CAS latency, the better A RAM kit with a CAS of 16 takes 16 RAM clock cycles to complete this task. The lower the CAS latency, the better. ... It's important to note that two different RAM kits with the same data transfer rate, for example DDR4-3200, can have different CAS timings.9 mar 2019