With the game physics engine running at 30Hz on the server, Splash Damage defaults the client frame rate to 60 frames per second (fps). However, they understood that players with high-end systems may wish to unlock the frame rate, which is made possible via the com_unlockFPS console variable or cvar. Unless the value of com_unlockFPS is 1, the game will attempt to maintain a constant frame rate of 30fps. Note that com_unlockFPS only applies when connected to a server.
When the frame rate is unlocked, two additional variables come into play. The first variable is com_unlock_timingMethod, which can be set a value of 0, 1 or 2. The second variable is com_unlock_maxFPS, which is managed in increments of 30, and caps the maximum frame rate the game will attempt to achieve. Note that com_unlock_maxFPS only applies when com_unlock_timingMethod is set to 1 or 2.
0 - Maximum frame rate without regard to the "smoothness" of the frame rate
1 - Lower frame rate than method 0, but slightly smoother
2 - Lowest frame rate, but the most smooth
There are various methods to set console variables one of which is to create an autoexec.cfg file. The autoexec.cfg file is a text file that resides under the /base directory and is parsed when the game executes.
Note that when a variable is modified via the seta command, it is permanently changed unless it is modified again with another seta command. To change a variable temporarily, use the set command.