9999 is a weird value. the default is a multiple of 8, keep it 8196 as a maximum.
Stojke look at his map I don't have VHE anymore
One thing that can sometimes fix problems like this one is selecting all your objects, copying them, and pasting them in a completely new map, then recompiling it. As dodgy as that sounds it has fixed problems for me before.
E-polys are entity versions of W-polys (world polygons). There are three types of things drawn within HL; the World polygons, the Entity polygons, and sprites. Entity polygons come from both entities like func_wall or func_door, and from player models and any other models you might have in the map.
So when you have 20 players, your map would have like 5000 additional E-polys if we assume each player model is 250 polys.
My maps usually have like 1000 epolys in one area, and on a full server that can go to 8000 and anything further would get really laggy for some people.
To check how much polys each area has, type developer 1 into the console, and then type r_speeds (while within your map). It will now display as you walk around.
If it's anything crazy like 3000+ in any one area, then that's your problem, and you should reduce that amount.