It's funny how little info there is on this subject, and anytime someone asks in a forum it's always the same replies "just get a 1-worker license and see if it works, upgrade it if it gets maxed out". Not super helpful imo, but it is what it is.
I was stuck thinking if I should get the 2-worker, 4-worker, or if I'd need the unlimited. I ended up sort of splitting the difference by buying a 3-worker license from cpanel, it's $1 cheaper than buying the 2-worker license from litespeed.
It worked fine, I never see any of the 3 worker processes going over 20-30% CPU utilization each, so I could probably have been fine with a 2-worker, but I'm happy with where I'm at with the 3-worker license. It seems like I would probably run out of other system resources before my 3 workers became overused.
My servers are pretty big and busy, 50cpu/250ram, serving around a million visits per day each, probably around 2 million pageviews per day including bots.
We utilize Cloudflare on 100% of sites which helps take a good chunk of load off. I've read other users that didn't use Cloudflare got much worse performance out of their litespeed workers as far as the amount of traffic they could handle, for whatever that's worth.
I think for a server of <10cpu and <50gb ram the 1-worker license would be fine. Then for 10-20cpu/50-100gb ram I would go for 2-worker. Assuming your database and everything else is dialed in for performance at least.
