Originally Posted by einstein_314
WOW! That's incredible! So this sys_physics 0 or 1....what exactly does it do? He says that setting to to 0 will decrease framerate a whole bunch....but with it at 1 the framerate is crap because the CPU is bogged down with physics. Hmm, I guess maybe it give physics a priority or something? That's pretty cool.
sys_physics_cpu 1 - thats the default setting, unsyncs physics from the GPU framerate. It's better to have physical objects to get slowed down instead of graphics and physics during actual gameplay.
sys_physics_cpu 0 - this one syncs physics with the gpu and makes the recording possible
fixed_time_step xx - this cvar changes the general "speed" of the game, you can play it slowmo or much higher speed than normal. It's pretty funny to use this one in SP.
Slowmo value is something like 0.01 and speed up something like 0.09.
Here in this thread you can read in detail what the guy did: