Another point is that, even if a bit of latency isn't noticeable (say, 20 ms), when added to other sources of latency it can make things noticeably worse. EDIT

Another point is that, even if a bit of latency isn't noticeable (say, 20 ms), when added to other sources of latency it can make things noticeably worse. EDIT: Which the original author said better than me: > Another problem with this line of reasoning is that the full pipeline from keypress to screen update is quite long and if you say that it’s always fine to add 10ms here and 10ms there, you end up with a much larger amount of bloat through the entire pipeline, which is how we got where we are today, where can buy a system with the CPU that gives you the fastest single-threaded performance money can buy and get 6x the latency of a machine from the 70s.