This will help a little bit : You should tweak your config until you find the settings that best fit your machine. *NOTE* prior to tweeking your config, please back it up !
fps_max 101.1
r_decals 0
mp_decals 0
net_graph 0
cl_showfps 1
cl_interp 0.01
cl_radartype 1
cl_show_bloodspray 0
cl_ejectbrass 0
cl_scalecrosshair 1
cl_ejectbrass 0
cl_show_splashes 0
cl_show_bloodspray 0
r_3dsky 0
r_shadows 0
r_eyes 0
r_teeth 0
r_drawrain 0
r_dynamic 0
r_modellodscale 0.1
r_drawlights 0
r_DispUseStaticMeshes 0
fog_enable 0
muzzleflash_light 0