Hi Voodoo,
Refer to the chart on DDR4 write MB/sec, similar to Chia plotting. This also affect 5950x as AMD is using the same Infinity Fabric design. For optimization, use Linux and overclock the memory clock speed. Use multiple ssd instead of 1 ssd to avoid bottleneck on pcie or sata. Maybe Raid0 will help too.
Else sell ur AMD CPU and switch to Intel one for plotting.