[haZh]

Same here. Mine is ranging from 30 - 75 FPS in-game with "stats" command. Hardly doubt your sys_ticrate "500" has anything to do with the actual server FPS, because if you are trying to force it on a weak set of hardware, server will go unstable. What you got with the old HLDS is most likely an unstable 500 FPS, meanwhile reHLDS seems to have brought it down to a much more believable and stable FPS with your hardware.

My server specs: Vultr $2.5/mo plan, 1 Core, 512MB RAM, Ubuntu 18.04 LTS

UPDATE: I was wrong. You should type 'stats' command in the server console, not in the game console. There you will see the correct server FPS that you force using sys_ticrate. Mine is ranging from 500 - 800 FPS when 1 player is online with sys_ticrate "1000" in a Google Cloud f1-micro instance.