Understanding Lagometer

Quake 3 Lagometer

The lagometer can be enabled by simply bringing down the console in "Quake III Arena" by typing /cg_lagometer 1 and to disable it /cg_lagometer 0. The lagometer is really a useful tool once it's "full" power is understood. You can actually tell alot about you and the servers connection with the lagometer. When you have a complainer spamming "Server LAG!!", you can check it out yourself. Here is a little description of what this all means:

The top line is the server. It is a fast blue line if frames are being rendered in time with the server updates. Should it have "yellow hills" then server snapshots are being dropped, this is a server problem but as a player you can reduce your com_maxFPS, snaps, or tweak your graphic settings to raise your average framerate (cg_drawFPS 1) so it is always above your snaps setting (use in increments of 20 when you can, Quake is a 20Hz engine).

The bottom line is the players connection. Normally green indicating a received snapshot, the higher the lines the higher your ping. A yellow line indicates your rejecting packets (you're at your max Rate) and red that the packet was lost. In the case of yellow increase your rate or lower your snaps. When it is red packets are being lost from the server to you, this is usually a server or internet congestion/routing problem. Remember Red is dead, change server's or ISP's.

LAGOMETER EXAMPLES

	Perfect playing on a Local LAN Ping = 5			Running Around Ping =< 300			Hitch < 500 Small Jitters or Nothing at All
	Running Around Ping =< 100			Running Around Ping =< 500			Hitch 500 - 1000 - Delayed Action and Medium Player Spike
	Firing Continuously Ping =< 100			Respawning After Death			Hitch 1000 - 2000. Delayed Action and Major Player Spike
	Jumping and Firing Ping =< 100			Major Action with LPB Player			Baby Ramp. Delayed Action and Small Player Spike
	Internet Delays Ping =< 100			Barely Connected Ping >= 900			Rolling Hills. Jittery Play and Major Player Spikes
	CPU Starved for Power Ping =< 100			Disconnect Warning Ping >= 999			Server Stalled. Stops Player Action

The upper graph (blue/yellow) slides one pixel for every rendered frame. Blue lines below the baseline mean that the frame is interpolating between two valid snapshots. Yellow lines above the baseline mean the frame is extrapolating beyond the latest valid time. The length of the line is proportional to the time.

The lower graph (green/yellow/red) slides one pixel for every received snapshot. By default, snapshots come 20 times a second, so if you are running >20 fps, the top graph will move faster, and vice versa. A red bar means the snapshot was dropped by the network. Green and yellow bars are properly received snapshots, with the height of the bar proportional to the ping. A yellow bar indicates that the previous snapshot was intentionally suppressed to stay under the rate limit.