I never said anything about a magical 3000 nor was I implying that the lowest I get is 20FPS which is still fine for most parts. I am attaching screen shots but of course Photoshop is a great tool which i could have used to change the pictures just to prove a point...
Those models arnt using high textures which you stated you selected in your original post... (I know this because I do video game modelling and understand how they are rendered within an engine in different stages for different settings)
Second, now your stating your minimum fps is 20 whereas before it was 30. Thirdly theres like what? 8 zombies on the screen?
Edit: Ok looking again theres around 19 actual zombies on screen in a single frame. Some a fair distance away from you and also it seems like a custom map which is using hardly any triangles and seems fairly basic, comparing that with an actual valve made map would be a completely different scenario. Your FPS would be even worse.
and 20 fps is not good at all, anything less than 30 fps is deemed borderline unplayable. Your average TV channel (none High def) run at a framerate of 24 frames a second. The human eye cant really tell much different above this number when looking at a moving image. Anything under 24 is when your eye can start telling there are seperate images being rendered or in our terms... Lag