[Rhapsody]

Code:

fps_max 1000
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
mat_queue_mode -1
studio_queue_mode 1
gmod_mcore_test 1

Add these to your autoexec.cfg or another file (I have one called multicore.cfg, I type exec multicore to run it after I join the server). This enables experimental multicore rendering, which improves performance by a very considerable margin. The downside is that it's just that; experimental. I don't really crash that often but I think those times I do can be attributed to this.