I figured it out.
Feed rate, in general, is the speed of a single print move, from point A to point B. It is specified with every G1 command that commands a move. Setting the feed rate on the printer console will scale the feed rate of every move the printer makes. The Cura "Print speed" setting is used as a basis to set the print speed (Feed rate) of different line types. Eg. Infil is 100% of this speed, walls are 50% of this speed, etc.
There are several other settings that will make Cura will decide not to use the speed that you set.
- Minimum layer time. In my case, this prevented the walls of the calibration cube from reaching the maximum speed. They were slowed down until so that each layer took at least 10 seconds.
- Lines that overhangs are scaled to a percentage of what they would normally print at.
- Bridge speed settings are found in the experimental settings, and if enabled they will override the speed for bridges.
In addition, the printer's acceleration setting may prevent it from reaching the maximum speed. You can see this if you issue this command during printing:
M201 X50 Y50 ; Set max acceleration
The print will slow down a lot until you set it back to the default. The printer will accelerate and decelerate slowly and simply never reach the maximum speed over short distances. The default in the Marlin firmware (for Ender) seems to be:
M201 X500 Y500 ; Set max acceleration