What is this Cisco Guy doing writing about Apple MacBook issues? Things that plagued me for a lengthy period of time, that have a quick fix, is worth sharing with my fellow IT man/woman. Sometime ago my MacBook had a few strange issues. External Apple Thunderbolt 27" monitors would cause high CPU. This took long enough to figure out what was causing the high CPU. Unplug the monitors, the CPU would go down for a bit. Plug it back in, CPU would go up after several minutes.