I assume its this one?
Are you tired of lag because of your Potato PC? Well this is the guide for you! I am going to teach you how to reduce lag by lowering the graphics settings so you can enjoy Garry's Mod ...
steamcommunity.com
I think I had similar a few years ago using
@Creepis one but I could be wrong, which was this one
Removed as I do more harm than good. DM me if you need assistance. Below is the only things you should look out for/use.
r_3dsky 0
r_shadows 0
r_drawdetailprops 0
required commands for multithreading (gmod_mcore_test 1 does not work without these)
gmod_mcore_test 1
mat_queue_mode -1
cl_threaded_bone_setup 1
cl_threaded_client_leaf_system 1
r_threaded_client_shadow_manager 1
r_threaded_particles 1
r_threaded_renderables 1
r_queued_ropes 1
studio_queue_mode 1
use the correct beta branch for 64-bit. If this crashes your game use the one that's an update behind...