I know, it is surprising, While yes, Hyper-V is disabled by default in the OS. Hardware Virtualization Technology is enabled by default on the BIOS level. (At least that’s how it was on my motherboard). I know because I flash my BIOS firmware very frequently, as soon as they release a new firmware BIOS version. After that I always reset all BIOS settings to its Factory Default values. And the Hardware Virtualization Technology setting is always enabled on Factory default setting. I usually leave it alone since that’s just how the factory default setting is.
I’m not even doing any virtualization on my own, like I said, I don’t have VMs running, my Hyper-V is disabled as it is by default in Windows 10.
I’m with you here, it’s surprising, it doesn’t make sense, and it shouldn’t help at all. Yet the result speaks for itself, when I leave it on default, (HVT enabled, Hyper V disabled) I’m getting low 10-15 FPS with Limited by Main thread at any graphics setting level. Once I manually disable HVT on the BIOS, making me set it away from the factory default setting, my fps jumps to stable 30 FPS on ULTRA, while I can push more than that on lower graphics settings, with overall bootleneck to no longer be Limited by Main thread but Limited on GPU.
I didn’t find about this “workaround” myself, I wouldn’t even think about this since like I said, before I install MSFS I reflashed my BIOS, clean install Windows 10 (as it was just released 21H1 version), and I kept everything at their factory default setting. But I’m getting low FPS, until I stumbled upon this “solved” topic, which suggest to disable the HVT on the BIOS. I merely follow the advice, and by some miracle that makes no sense, it does help my performance, as it did help on their performance issue in that topic.