a problem with quake mods Thread

i have a pretty old laptop that runs on an intel i7 with a base clock of 1.8 ghz, and i play the shit out of quake that's capped at 90 fps. however, the mods for the game would have their framerate drop to 20-40 fps. i've only tried arcane dimensions, slayer's testaments and ravenkeep so far. i have quakespasm installed and i run said mods on sqlauncher. what is the cause for the frame dips and is there a fix for this problem? thanks in advance.