Depending how you&#x27;re measuring it, I believe it could be because urxvt&#x27;s output is buffered by default whereas xterm&#x27;s isn&#x27;t. That may mean 16.7ms (= 1 second &#x2F; 60Hz) is added to the measured latency, though the extra time would have no effect in practice.<p>ed: or maybe thats excluded from the measurement but urxvt is double buffered by default?