[backwards]

Single threaded just means the servers only utilize one thread. Other applications can still use that thread except it fills the pipeline more of what that core can produce in cpu cycles per second. The more stuff you have in its processing the lane the longer it takes for everything to complete. Logically think about it, if you only have 8 cores and run more than 8 applications/services at a single time then this shouldn't work but that's not the case. Source engine has no limit to how many servers you can run on a single thread, it's just that the performance required for more players/tickrate/packets on modern cpus are best for csgo servers to be ran on all separate threads.