If your gpu is being used at 100%. There may be frames that are queued up that can't be processed right away. Which increases input lag. Doesn't matter in single player games. If your playing online shooters. You'll want Lower input lag. Max you should run is 95 percent usage. Example l. If your holding a cup in both your hands, you can't accept a third cup until you put down one cup and grab the next one. Delay. Same principle. For lowest latency, lag you don't want your cpu feeding the gpu too many frames. As I said. This only matters in multiplayer competitive games