Noticed a definite increase in lag in comparison to 1.7.4. Java process used > 100% as reported by "top" shell command. Monitoring CPU usage while a single player traveled around indicated it was related to proximity to villages. Lag did not occur in Nether, The End, or at places distant from Villages. Lag increased as size of village increased. CPU usage was almost entirely in a single java thread (as reported by "top").