I'm using a Seiki 4k display model SE39UY04 connected via HDMI with a Retina, 15-inch, Early 2013 MacBook Pro at 3840x2160 @ 30 Hz running Mavericks. I've noticed that with the laptop closed and only displaying on the external display, I sometimes find in Chrome that bluetooth attached keyboard response is very sluggish. For example, I can type a sentence on a web page but nothing appears at first, then a few words, and finally the rest appears quickly, however, the delay between typing and completion of it showing up can be 30 seconds or so. I've looked at the
Activity Monitor and do not see any CPU hog, the machine is relatively idle and the fan is not running on the laptop.
How can I figure out the cause of this intermittent delay that seems to have appeared with the introduction of the very large external display?