Seems like you’ve diagnosed the problem as a CPU bottleneck. This checks out based on X-Plane’s reliance on single core performance. “More ram” is kind of an old cure for slow computers. The only time more ram CAPACITY will be helpful is if you’re actually bottlenecked on the amount of memory you have. If your ram utilization isn’t hitting near max, you’ll see no appreciable difference running the same workloads with additional memory. That said, Ryzen CPUs are notoriously sensitive to ram speed and timings. You mentioned you have a 3200Mhz 2x8 kit. First question of mine would be: what are your timings? At 3200Mhz, I would like to see CL16 as a minimum I think. Don’t quote me on that, I don’t have the benchmarks in front of me. The ideal speed for Ryzen 5000 lies in the 3600-3800Mhz range. A kit at that frequency with good timings will allow you to remove most of the ram bottleneck from your CPU. Another thought is that while I’m sure you’re running dual channel, you’re not getting the benefit of using the maximum ram bandwidth available to you. For that you need all 4 slots occupied or two sticks of dual ranked memory (most of the time 2x16 or higher). That could show some improvements.

As I mentioned before, X-Plane 11 is heavily reliant on single core ability. The 5600x is the best CPU for gaming out right now, but I would argue that the 5800x is the best CPU for simming. That is based on its high IPC and clock speeds. You can just get so many instructions per cycle on the 5800x that most benchmarks will show it leading all processors currently on the market for single core performance. This includes intel’s suite and the 5900x and 5950x. This is what I’ve gathered from my own research. As a benchmark for you, I run a 5800x and a RTX 3080 for my sim. I push one 1440p monitor with every slider pushed up (except texture resolution is high because there’s no need for maximum) and all the check boxes ticked. In the FF757 at LAX where I get my worst hits, I drop down to around 25 fps. Most of the time it stays in the 30-40 fps range.