I have this TV and if I don't enable game mode in the general settings while using a 24p input, using the "PC" label has no effect whatsoever; all special non-game mode settings can be enabled or changed, and input lag isn't reduced. If I use both setting together, the display disables a ton of picture settings (e.g., motion control), and the lag is significantly reduced. I suspect your input lag timings might not apply for this display as a result. I'm guessing you don't have the display anymore, so you probably can't confirm what I'm saying, but I promise you this is how the display actually works.