I would suggest against using a long cable especially if it's a gaming machine. The more distance between the monitor and computer, the more latency you introduce.
You are aware that the signal travels near the speed of light right? No cable could introduce latency because of length, the signal would attenuate to nothing long before you could notice the lag. The only reason you notice lag in a phone conversation with someone far away is that the signal must be amplified many times over which introduces the slow downs. If nanoseconds concern you I might have to call you superman.