Question about lag in Dual Screen PC

I have a second display in my pc, which is an CRT TV that i use for old games through emuladors and 1st display is an LCD. Should i connect only the tv for a lag free experience? or maybe i can play without input lag through the tv even with the LCD connected.

I don’t know for sure.

tks in advance

CRT almost garantee lag free play, but most newer PC LCD monitors are also lag free
For more info read here