geo time in ms for level geometry and sky rendering
ent time for entity rendering
par time for particles rendering
drw time for draw_ functions
pan time for panels, texts and screen entities rendering (and for the 3D card to flush its command buffer)
ref time for screen refresh, monitor sync, and fps_max idling
srv time for entity updates and client/server communication
fnc time for script execution
phy time for physics

so my first guess is a graphics card related issue, but if it is fine with other levels you could strip down the project until you find the reason... so basically I can say nothing clever for example on my old pc I got high ref and srv values (really without reason) and slow fps.