Disabling SMT to increase performance in the gaming community has been around for a long time and something I've personally done for years, however it never was this big of a gap. Disabling SMT will almost always reduce microstuttering/stuttering at the loss of a bit of average FPS. The most important distinction here however is W11. The thread scheduler in W11 was the biggest change from W10 and while Intel said you had to swap to W11 to utilize their CPUs properly, they work under W10 too.
While In a lot of cases loading up the 'best' cores the most helps for overall throughput, it's not a best case scenario for latency sensitive applications. Games are very much latency sensitive as well as throughput sensitive.
Taking this further, you'll actually find that having CPPC on also reduces performance. While it might help with one specific application that is utilizing one core, windows will over load the 'best' cores further exasperating this situation. While you can't turn CPPC off anymore in modern Ryzens specifically, you can by disabling other power management options which has pros/cons to it. CPPC is under a power management feature called PSS Support (which is a few features, but CPPC is what we want).
After disabling CPPC you'll see thread loading to be more uniform across all cores. This is important for multithreaded and even single threaded applications. So a bunch of extra threads aren't being thrown on a CPU that might be all of 5% faster, while other cores have plenty of headroom available.
CPPC/SMT/W11 thread scheduler are all things at work here and need to be tweaked.
Also going to point out using Process Lasso or other applications to 'band aid' a game to every other core is NOT the same thing as natively disabling SMT. Windows will still try to utilize the other half of the virtual core creating thread contention. There are a lot of windows processes that can't be touched, if people using lasso even bother with everything that can outside of the game.
