Update 'FAQ'

NGnius 2023-10-30 20:32:48 +00:00
parent fb2253a293
commit 40c1eeae31

2
FAQ.md

@ -44,7 +44,7 @@ The SMT toggle in PowerTools doesn't technically disable SMT.
Instead it disables every second CPU, since every group of two CPUs is one logical CPU core. Instead it disables every second CPU, since every group of two CPUs is one logical CPU core.
## Why does disabling SMT speed up some games? ## Why does disabling SMT speed up some games?
I don't really know. There is a bug before SteamOS 3.5 which caused cache issues when SMT was enabled, but there have been reports of some games still benefiting from SMT being disabled on SteamOS 3.5+ too. I don't really know. There is a bug before SteamOS 3.5 which causes cache issues when SMT was enabled, but there have been reports of some games still benefiting from SMT being disabled on SteamOS 3.5+ too.
My theory, which is backed by exactly zero research and experiments, is that since SMT increases performance of a single core by less than 100% (usually it's closer to 30-50%), that 150% performance gets split between two threads, effectively reducing each thread's performance to 75% when both threads are under heavy load. My theory, which is backed by exactly zero research and experiments, is that since SMT increases performance of a single core by less than 100% (usually it's closer to 30-50%), that 150% performance gets split between two threads, effectively reducing each thread's performance to 75% when both threads are under heavy load.
It would then follow that disabling one of those threads would restore the remaining thread to 100% performance. It would then follow that disabling one of those threads would restore the remaining thread to 100% performance.