You&#x27;re right, urxvt refreshes at a maximum of 60Hz (line 1021 in <a href="http:&#x2F;&#x2F;cvs.schmorp.de&#x2F;rxvt-unicode&#x2F;src&#x2F;command.C?view=markup" rel="nofollow">http:&#x2F;&#x2F;cvs.schmorp.de&#x2F;rxvt-unicode&#x2F;src&#x2F;command.C?view=markup</a>). Above, I mistakenly measured only urxvt. Rxvt does a select() with a timeout of 5ms before redrawing (lines 1600 and 1664 in &quot;src&#x2F;command.c&quot;). The total latency with rxvt is about 5.7ms.