Quake3World

I was wonderin if there is a timedemo command in Quake4, just like there was in Doom3?

In Quake3 there was a timedemo command, you had to type timedemo 1 and after that demo four, where "four" was the name of the demo in version 1.32.

In Doom3 however, by typing timedemo Doom3 launched a demo directly, and displayed a summary of the benchmark after the demo run was completed.

Does this exists in Quake4 too?

Yes, it exists, but Q4 didn't ship with any demos out of the box. You can use "timeDemo" to time a .demo, and "playNetTimeDemo" to time a.netdemo you record or download.