During a flight this morning from CYTZ to KPVD in the Kodiak, I was experiencing poor terrian LOD and pop-in even in fairly rural areas. I checked my CPU utilization and found very low usage. Why would this occur with so much CPU headroom? I have a 1.2Gbps connection (speedtest showed actual 880 Mbps). My system specs are in my profile.
Because you are gaming and not processing videos or number crunching which might utilise all your cores to the full. Mainthread is but a single core and is mostly what decides on your performance, once at 100% there is no more no matter how unused other cores are. MSFS has to sync data from various sources and more hyperthreading than necessary will only increase latency and this is especially so for those on the recommended low-end spec. Remember that MSFS is for everyone.