I don't know who originally authored this, but it has given me a huge boost in performance in Portal and other Source engine games. I'm running Ubuntu 7.10 on a P4@2.4GHz, 1Gig RAM and an AGP 4x, NV 7600 GT and I can run Portal in a 1024x768 window quite easily.
// Legal FPS Config v2.0 (No Sv_Cheats 1 / CAL Legal / CEVO Legal / Zblock Legal)
// Updated : 21 May 2007
// Cvars Value for the command
//Rates Settings
cl_lagcomp_errorcheck "1"
cl_lagcompensation "1"
cl_interpolate "1"
sv_unlag "1"
cl_interp "0.01"
cl_smooth "1"
cl_smoothtime "0.01"
cl_resend "6"
cl_pred_optimize "2"
net_maxfragments "1280"
cl_timeout "30"
cl_predictweapons "1"
net_maxfragments "1280"
//Ingame Quality
jpeg_quality "100"
mat_monitorgamma "2.2"
cl_lagcompensation "1"
mat_debug_autoexposure "0"
mat_debug_bloom "0"
mat_debug_postprocessing_effects "0"
mat_debug_process_halfscreen "0"
mat_debugalttab "0"
mat_debugdepth "0"
mat_debugdepthmode "0"
mat_debugdepthval "128"
mat_force_bloom "0"
mat_hdroverbrightrange "16"
mat_leafvis "0"
mat_norendering "0"
mat_parallaxmap "0"
mat_debugdepthvalmax "256"
cl_allowdownload "0"
mat_bloomamount_rate "0.05f"
mat_bumpbasis "0"
cl_allowupload "0"
cl_forcepreload "1"
cl_drawmonitors "0"
gl_clear "0"
texture_budget_background_alpha "9999999"
texture_budget_panel_height "0"
texture_budget_panel_width "0"
mat_compressedtextures "1"
mat_filterlightmaps "1"
mat_forcehardwaresync "0"
mat_reducefillrate "1"
mat_disable_bloom "1"
r_maxdlights "32"
mat_wateroverlaysize "8"
cl_show_splashes "0"
cl_detail_avoid_force "0"
cl_detail_avoid_radius "0"
cl_detail_avoid_recover_speed "0"
cl_detail_max_sway "0"
muzzleflash_light "0"
mat_hdr_enabled "0"
r_maxnewsamples "0"
r_maxsampledist "0"
r_norefresh "0"
r_minnewsamples "0"
mat_parallaxmap "0"
mat_hdr_level "0"
mat_forceaniso "0"
mat_bloomscale "0"
mat_forcemanagedtextureintohardware "0"
mat_fastnobump "1"
cl_wpn_sway_interp "0"
mat_trilinear "0"
r_TransitionSensitivity "0"
mat_antialias "0"
mat_specular "0"
mat_bumpmap "0"
mat_showlightmappage "-1"
mat_bufferprimitives "1"
mat_disable_lightwarp "1"
budget_show_history "0"
mat_framebuffercopyoverlaysize "0"
budget_history_range_ms "5"
mat_surfacemat "0"
r_forcewaterleaf "0"
r_updaterefracttexture "0"
mat_disable_ps_patch "1"
mat_envmapsize "0"
mat_envmaptgasize "0"
mat_disable_fancy_blending "1"
mat_autoexposure_max "0"
mat_autoexposure_min "0"
budget_history_numsamplesvisible "0"
mat_picmip "0"
mat_clipz "1"
r_phong "0"
lod_TransitionDist "0"
mat_vsync "0"
r_decal_cullsize "0"
r_shadows "1"
r_eyes "0"
r_eyeglintlodpixels "0"
r_eyesize "0"
r_eyeshift_z "0"
r_shadowrendertotexture "1"
flex_smooth "0"
r_worldlightmin "0"
r_worldlights "0"
r_flex "0"
r_eyeshift_y "0"
r_worldlightmin "0"
mat_shadowstate "0"
r_worldlights "0"
r_eyeshift_x "0"
r_eyemove "0"
r_eyegloss "0"
r_teeth "0"
r_decals "1"
r_waterforceexpensive "1"
r_worldlightmin "0.0002"
r_waterforcereflectentities "0"
r_waterforceexpensive "0"
r_worldlights "2"
r_PhysPropStaticLighting "0"
r_cheapwaterend "1"
r_cheapwaterstart "1"
r_updaterefracttexture "0"
r_WaterDrawReflection "0"
r_WaterDrawRefraction "0"
showhitlocation "1"
r_ambientfraction "0.1"
r_waterdrawreflection "0"
r_waterforceexpensive "0"
r_drawdetailprops "1"
r_ropetranslucent "0"
r_dynamic "0"
r_avglight "1"
r_lightaverage "1"
g_ragdoll_fadespeed "0"
g_ragdoll_important_maxcount "0"
g_ragdoll_lvfadespeed "0"
g_ragdoll_maxcount "0"
lod_enable "1"
cl_autohelp "0"
cl_c4progressbar "1"
hud_centerid "1"
dsp_water "14"
blink_duration "0"
hud_fastswitch "1"
closecaption "0"
//Sound Settings
snd_flushasync
snd_mixahead "0.1"
snd_async_fullyasync "0"
snd_digital_surround "1"
dsp_enhance_stereo "0"
dsp_slow_cpu "1"
dsp_spatial "40"
dsp_speaker "50"
dsp_volume "2"
hud_centerid "1"
cl_downloadfilter "nosounds"
snd_profile "0"
volume "1"
sv_voiceenable "1"
voice_scale "1"
voice_modenable "1"
voice_enable "1"
// These cvars boost your fps dramaticly
r_3dnow "1"
r_3dsky "0"
r_sse "1"
r_sse2 "1"
r_mmx "1"
props_break_max_pieces "0"
func_break_max_pieces "0"
props_break_max_pieces_perframe "0"
fps_max "30"
con_enable "1"
weapon_showproficiency "1"
//Ropes
rope_smooth_maxalphawidth "0"
rope_smooth_maxalpha "0"
rope_smooth_enlarge "0"
rope_wind_dist "0.01"
rope_subdiv "0"
rope_smooth_minwidth "0"
rope_smooth_minalpha "0"
rope_averagelight "0"
rope_smooth "0"
rope_shake "0"
rope_collide "0"
//Models
cl_ragdoll_physics_enable "0"
r_modellodscale "1"
cl_ragdoll_collide "1"
cl_phys_props_max "50"
r_maxmodeldecal "0"
cl_minmodels "1"
cl_min_ct "1"
cl_min_t "1"
r_drawmodeldecals "0"
//Blood Settings
violence_ablood "1"
violence_agibs "1"
violence_hblood "1"
violence_hgibs "1"
//Restrict the server commands
cl_restrict_server_commands "0"
//my commands
cl_crosshairscale 9999
sensitivity 3.0
net_graph 3
net_graphpos 1
rate 100000
cl_crosshairalpha 999 // _bright crosshair_
cl_radaralpha 255 // _maximum radar brightness_
cl_radartype 1 // _enables solid radar_
cl_crosshaircolor 0 // _green crosshair_
alias tg_clr "incrementvar cl_crosshaircolor 0 4 1"
bind ";" "tg_clr" // _crosshair color adjuster_
alias crssw "cl_crosshairusealpha 1; tg_crs"
alias tg_crs "cl_crosshairalpha 800; alias crssw tg_crs1"
alias tg_crs1 "cl_crosshairalpha 200; alias crssw tg_crs2"
alias tg_crs2 "cl_crosshairalpha 100; alias crssw tg_crs3"
alias tg_crs3 "cl_crosshairalpha 200; alias crssw tg_crs"
bind "'" "crssw" // _crosshair transparency adjuster_
clear
echo "Spam's config loaded"