This is the best result so far. If you post your config file we could try it on some different hardware.
I found one tweaks online, and just pasted it at the end of the q3config file. It might be possible to optimize it more.
// generated by mb`Gabr1el, do modify
// unbindall
// Spec
seta bot_nochat "1"
seta com_blindlyLoadDLLs "1"
seta scr_conspeed "999"
seta com_introplayed "1"
seta s_ambient "0"
// Personal Options
// seta cg_fov "100"
seta cg_drawGun "0" // 2
// Rail
seta r_railSegmentLength "0"
seta r_railCoreWidth "1"
seta r_railWidth "0"
seta cg_railTrailTime "100"
seta cg_teamRails "1"
// Team Messages
seta cg_drawTeamOverlay "0"
// seta cg_MaxlocationWidth "10"
// Player Bobbing
seta cg_runpitch "0"
seta cg_runroll "0"
seta cg_bobup "0"
seta cg_bobpitch "0"
seta cg_bobroll "0"
// graphics
seta r_mode "3"
seta r_picmip "5"
seta r_lodbias "2"
seta r_vertexLight "1"
seta r_detailtextures "0"
// seta r_lodscale "999" // c
seta r_subdivisions "80" // 999
seta r_roundImagesDown "999"
// seta r_lodcurveerror "999"
seta r_depthbits "16"
seta r_textureMode "GL_NEAREST"
// render settings
seta r_fastsky "1"
seta r_fullscreen "1"
seta r_customaspect "1"
seta r_ignoreGLErrors "1"
seta r_ignoreFastPath "0"
seta r_preloadTextures "0" // 1
seta r_simpleMipMaps "1"
seta r_colorbits "0"
seta r_texturebits "0"
seta r_dlightBacks "0"
seta r_dynamiclight "0"
seta r_glDriver "opengl32"
seta r_allowExtensions "1"
seta r_ext_multitexture "1"
seta r_ext_gamma_control "1"
seta r_ext_texture_env_add "0"
seta r_ext_compress_textures "1" // -
seta r_ext_compressed_textures "1"
seta r_ext_compiled_vertex_array "1"
// seta r_ext_compiled_vertex_arrays "1"
// sound
seta s_khz "11"
seta in_midi "0"
seta in_joystick "0"
seta in_midiport "0"
seta in_mididevice "0"
seta in_midichannel "0"
seta s_musicvolume "0"
seta cg_stereoSeparation "0.4"
seta s_rolloff "0.0"
seta s_compression "1"
seta s_separation "0.5"
seta s_mixPreStep "0.05"
seta s_mixahead "0.065" // 0.079 oder höher bei soundprobs
seta s_loadas8bit "1"
seta s_doppler "0"
// Promode, CPMA
seta cg_fallkick "0"
seta cg_damagekick "0"
seta cg_damagedraw "0"
seta ch_drawspeed "0"
seta cg_smokegrowth_gl "0"
seta cg_smokegrowth_rl "0"
seta cg_smokeradius_gl "0"
seta cg_smokeradius_rl "0"
seta cg_smoke_sg "0"
seta ch_drawWeaponSelect "0"
// Threewave
seta cg_drawping "0"
seta cg_itemlights "0" // mehr fps
seta cg_grapplemodel "0"
seta cg_forceGrappleModel "1"
seta cg_predictgrapple "0"
seta cg_teamGrapples "1"
seta cg_noProjectileTrail "1"
seta cg_teamGrenades "1"
seta cg_teamRails "1"
seta cg_selectEmpty "1"
seta cg_flagTrails "0"
seta cg_coloredliquids "0" // mehr fps
seta cg_pmFixes "1"
seta cg_noVoiceChats "0" // mehr ram
seta cg_drawTeamHealth "0"
// OSP Settings
seta cg_enableOSPHUD "0"
seta cg_deadbodyfilter "1"
seta cg_muzzleFlash "0"
seta cg_noProjectileTrail "1"
seta ch_statusbarFormat "0"
seta cg_drawDecals "0"
// tweaks
seta r_flares "0"
seta r_drawSun "0"
seta cg_drawFPS "0"
seta cg_drawTimer "0"
seta cg_scorePlums "0"
seta cg_gibs "0"
seta cg_marks "0"
seta com_blood "0"
seta cg_shadows "0"
seta cg_brassTime "0"
seta com_hunkMegs "128" // 84
seta com_zoneMegs "32"
seta com_soundMegs "16" // 8
seta cg_showPlayerLean "0"
seta cm_playerCurveClip "1"
seta cg_crosshairhealth "0"
seta cg_drawCrosshair "5"
seta cg_drawCrosshairNames "0"
seta cg_deferplayers "1"
seta r_facePlaneCull "1"
seta cg_forcemodel "1"
seta r_primitives "0"
seta cg_drawStatus "1"
seta cg_draw2D "1"
seta r_smp "0"
seta r_finish "0"
seta r_stereo "0"
seta s_leafnum "0"
seta r_stencilbits "8"
seta cg_drawkiller "0"
seta cg_lagometer "0"
seta cg_swapskins "0"
seta r_swapInterval "0"
seta cg_simpleItems "1"
seta r_inGameVideo "0"
seta cg_draw3dIcons "0"
seta cg_drawRewards "0"
seta cg_drawAttacker "0"
seta cg_drawSnapshot "0"
seta cg_drawAmmoWarning "0"
seta cg_errordecay "0"
seta vm_cgame "0"
seta vm_game "0"
seta vm_ui "0"
seta dmflags "0"
seta viewsize "100"
seta gl_polyblend "0"
// crosshair (einstellungen ganz unten um mögliche probleme mit der anzeige zu vermeiden)
seta cg_drawCrosshair "1"
seta cg_crosshairSize "16"
seta cg_drawCrosshairNames "0"
seta cg_crosshairHealth "0"