Two calculators
Both of these compare what listings state. Neither measures anything, and neither will tell you a thing is fine — the most either can say is that no listing here claims a limit, which is a smaller statement than it looks.
The video side
Choose a machine side, one of the 14 screens here, and one of the 7 modes those listings state. It answers with a stated cap, a not-stated, or no stated cap, and names the node that decided it.
Six printed rules, and any input that cannot change the answer is switched off with the reason shown.
The port side
Choose from the 10 keyboards and 12 mice here, add a screen, and it counts USB-A ports and Bluetooth pairings from what each listing states.
The formula is printed in full, including the fork for listings that state both routes.