Ok I am running Amd Athlon 1800 1.15 GHz 384 ram With a Gforce2
when I installed the game and attempted to play I got a whopping 2 fps to 4 fps to see what your FPS are put this in consol com_showFPS "1" or set com_showFPS "1" in config file
After I change some in game settings like
600x800 and low quality
Advance setting: I have High Quality Special affect checked yes and Enable Bump maps Yes all the rest are checked no.
After I did these things I am getting average of 21 fps to 35 fps and in high action areas they drop to 15 FPS
so this is what I did to my DoomConfig.
seta image_downSizeLimit "512" CHANGED THIS FROM 256
seta image_downSizeBumpLimit "512" CHANGED THIS FROM 256

Here is actual config just make a back up of your config and copy and paste. Try mine if you have an old Graphix card.

// IvL/FblnaU4w6bO89mN9XIzJKwdEz1acOB3LQ6Vj2NWPrRjcMHDUWwpZzE/zePncK8JfwT1h1fHq+5XRCsM=
unbindall
bind "TAB" "_impulse19"
bind "ENTER" "_button2"
bind "ESCAPE" "togglemenu"
bind "/" "_impulse14"
bind "0" "_impulse10"
bind "1" "_impulse0"
bind "2" "_impulse1"
bind "3" "_impulse2"
bind "4" "_impulse3"
bind "5" "_impulse4"
bind "6" "_impulse5"
bind "7" "_impulse6"
bind "8" "_impulse7"
bind "9" "_impulse8"
bind "[" "_impulse15"
bind "\\" "_mlook"
bind "]" "_impulse14"
bind "a" "_moveleft"
bind "c" "_movedown"
bind "d" "_moveright"
bind "f" "_impulse11"
bind "q" "_impulse9"
bind "r" "_impulse13"
bind "t" "clientMessageMode"
bind "y" "clientMessageMode 1"
bind "z" "_zoom"
bind "BACKSPACE" "clientDropWeapon"
bind "PAUSE" "pause"
bind "UPARROW" "_forward"
bind "DOWNARROW" "_back"
bind "LEFTARROW" "_moveLeft"
bind "RIGHTARROW" "_moveRight"
bind "ALT" "_strafe"
bind "CTRL" "_moveDown"
bind "SHIFT" "_forward"
bind "DEL" "_lookdown"
bind "PGDN" "_lookup"
bind "END" "_impulse18"
bind "F1" "_impulse28"
bind "F2" "_impulse29"
bind "F3" "_impulse17"
bind "F5" "savegame quick"
bind "F6" "_impulse20"
bind "F7" "_impulse22"
bind "F9" "loadgame quick"
bind "F12" "screenshot"
bind "KP_LEFTARROW" "_moveUp"
bind "KP_END" "_speed"
bind "KP_INS" "_impulse13"
bind "MOUSE1" "_attack"
bind "MOUSE3" "_zoom"
bind "MWHEELDOWN" "_impulse14"
bind "MWHEELUP" "_impulse15"
seta radiant_entityMode "0"
seta gui_mediumFontLimit "0.60"
seta gui_smallFontLimit "0.30"
seta net_socksPassword ""
seta net_socksUsername ""
seta net_socksPort "1080"
seta net_socksServer ""
seta net_socksEnabled "0"
seta win_ypos "22"
seta win_xpos "3"
seta sys_lang "english"
seta s_numberOfSpeakers "2"
seta s_doorDistanceAdd "150"
seta s_globalFraction "0.8"
seta s_subFraction "0.75"
seta s_playDefaultSound "1"
seta s_volume_dB "0"
seta s_meterTopTime "2000"
seta s_reverse "0"
seta s_spatializationDecay "2"
seta s_maxSoundsPerShader "1"
seta r_debugArrowStep "120"
seta r_debugLineWidth "1"
seta r_debugLineDepthTest "0"
seta r_cgFragmentProfile "best"
seta r_cgVertexProfile "best"
seta r_forceLoadImages "1"
seta r_shadows "0"
seta r_skipBump "0"
seta r_skipSpecular "1"
seta r_skipNewAmbient "0"
seta r_renderer "best"
seta r_brightness "1.595238"
seta r_gamma "1.3"
seta r_swapInterval "0"
seta r_useIndexBuffers "0"
seta r_customHeight "486"
seta r_customWidth "720"
seta r_fullscreen "1"
seta r_mode "4"
seta r_multiSamples "0"
seta image_downSizeLimit "512"
seta image_ignoreHighQuality "1"
seta image_downSizeBumpLimit "512"
seta image_downSizeSpecularLimit "64"
seta image_downSizeBump "1"
seta image_downSizeSpecular "1"
seta image_useCache "1"
seta image_cacheMegs "128"
seta image_cacheMinK "10240"
seta image_usePrecompressedTextures "1"
seta image_useNormalCompression "1"
seta image_useAllFormats "1"
seta image_useCompression "1"
seta image_roundDown "1"
seta image_forceDownSize "0"
seta image_downSize "1"
seta image_lodbias "0"
seta image_anisotropy "0"
seta image_filter "GL_LINEAR_MIPMAP_LINEAR"
seta gui_filter_gameType "0"
seta gui_filter_players "0"
seta gui_filter_password "0"
seta net_master4 ""
seta net_master3 ""
seta net_master2 ""
seta net_master1 ""
seta net_clientMaxRate "16000"
seta net_serverMaxClientRate "16000"
seta m_strafeSmooth "4"
seta m_smooth "1"
seta m_strafeScale "6.25"
seta m_yaw "0.022"
seta m_pitch "0.022"
seta sensitivity "5"
seta in_alwaysRun "0"
seta in_freeLook "1"
seta in_anglespeedkey "1.5"
seta in_pitchspeed "140"
seta in_yawspeed "140"
seta gui_configServerRate "0"
seta com_guid ""
seta com_showFPS "1"
seta com_purgeAll "1"
seta com_machineSpec "0"
seta g_decals "0"
seta g_projectileLights "0"
seta g_doubleVision "0"
seta g_muzzleFlash "0"
seta mod_validSkins "skins/characters/player/marine_mp;skins/characters/player/marine_mp_green;skins/characters/player/marine_mp_blue;skins/characters/player/marine_mp_red;skins/characters/player/marine_mp_yellow"
seta g_mapCycle "mapcycle"
seta g_voteFlags "0"
seta g_gameReviewPause "10"
seta g_countDown "10"
seta g_password ""
seta g_showBrass "1"
seta g_showProjectilePct "0"
seta g_showHud "1"
seta g_showPlayerShadow "0"
seta g_showcamerainfo "0"
seta g_healthTakeLimit "25"
seta g_healthTakeAmt "5"
seta g_healthTakeTime "5"
seta g_useDynamicProtection "1"
seta g_armorProtectionMP "0.6"
seta g_armorProtection "0.3"
seta g_damageScale "1"
seta g_nightmare "0"
seta g_bloodEffects "1"
seta ui_showGun "1"
seta ui_autoReload "1"
seta ui_autoSwitch "1"
seta ui_team "Blue"
seta ui_skin "skins/characters/player/marine_mp"
seta ui_name "Player"
seta si_spectators "1"
seta si_usePass "0"
seta si_warmup "0"
seta si_teamDamage "0"
seta si_timeLimit "10"
seta si_fragLimit "10"
seta si_maxPlayers "4"
seta si_map "game/mp/d3dm1"
seta si_gameType "singleplayer"
seta si_name "DOOM Server"
seta g_spectatorChat "0"

After I that game runs at bearable frame rate and I must say this is a beautful game! Hope this helps some one Sorry if I put this post in wrong spot did not see game support. Thank you for the quick reply of misplacement