just something for me to look at later http://developer.valvesoftware.com/wiki/Source_Multiplayer_Networking

the default rates are:

rate 10000
cl_cmdrate 30
cl_updaterate 20
cl_interp 0.1
cl_interp_ratio 2


rates for use

rate 30000
cl_cmdrate 101
cl_updaterate 101
cl_interp 0.04
cl_interp_ratio 1

rate 30000
cl_cmdrate 30
cl_updaterate 30
cl_interp 0.067

You are right about cmdrate and updaterate, but not about interp.

cl_interp = 2 / cl_updaterate
That's not ALWAYS right. In OB engine games and L4D, the minimal cl_interp you can have is:

cl_interp_ratio/cl_updaterate

cl_interp_ratio is by default 2, but you can set it to 1.

1/30=0.03

0.03 is the minimal interp and would be fine if your update rate stays on 30/s

Posted by Source Multiplayer Networking
Optimized setting for one client may not work for other clients
Do not just use settings from other clients without verifing them for your system