<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=us-ascii" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 9.00.8112.16440"></HEAD> <BODY> <DIV><FONT size=2 face=Arial><SPAN class=443493912-14122011>I see that after starting up, DrRacket constantly uses between 40 and 60 % of my two CPUs, even with empty definitions window and before doing anything by myself.</SPAN></FONT></DIV> <DIV><FONT size=2 face=Arial></FONT> </DIV> <DIV><SPAN class=443493912-14122011><FONT size=2 face=Arial>I use:</FONT></SPAN></DIV> <DIV><FONT face=Arial><FONT size=2>Welcome to DrRacket, version 5.2.0.6--2011-12-10(6fae172/a) [3m]</FONT></FONT></DIV> <DIV><FONT face=Arial><FONT size=2><SPAN class=443493912-14122011>without debugging and without preserving stacktrace.</SPAN></FONT></FONT></DIV> <DIV><FONT face=Arial><FONT size=2><SPAN class=443493912-14122011>Language determined by #lang line.</SPAN></FONT></FONT></DIV> <DIV><FONT face=Arial><FONT size=2><SPAN class=443493912-14122011>Disabling online expansion does not decrease CPU usage.</SPAN></FONT></FONT></DIV> <DIV><FONT face=Arial><FONT size=2><SPAN class=443493912-14122011></SPAN></FONT></FONT> </DIV> <DIV><FONT face=Arial><FONT size=2><SPAN class=443493912-14122011>What may be the reason for DrRacket to use so much CPU at moments I would expect it to be idle?</SPAN></FONT></FONT></DIV> <DIV><FONT face=Arial><FONT size=2><SPAN class=443493912-14122011>Thanks, Jos</SPAN></FONT></FONT></DIV></BODY></HTML>