How to solve server lag?

I’m not new at making servers or anything, but I’m getting really frustrated because I cannot figure out how to solve the server lag. It starts out fine, an as more players are joining, and start making things, it eventually gets to where everyone gets about 20-30 fps. Any tips, or suggestions would be great!

What map are you using

rp_downtown_v4_exl

Im not so sure what the best map to use is.

Maybe its the Server itself, low ram/CPU.

Alright, I found out that entities have a factor in the server lag. Although, there aren’t that many entities on the server when it lags. I’m just so confused…

“Maybe its the Server itself, low ram/CPU.”
Entities use also a bit of RAM, You know…?(Players ARE Entities)

net_graph 4 in console.

Check your stats.

Check your CPU usage in the server.

What host, gamemodes, and addons are you using?

Any errors in the console?

There are many factors for lag.

Turns out that it was an addon causing lag. It was removed from the server.