The documentation says "Profiling intervals may be given in Mega-, kilo-, or milli- seconds. For example, 1Ms (1 Megasecond), 2ms (2 milliseconds). If no units are specified, the default is seconds." But I suspect the default isn't seconds. I find that if I do -i100 I get different results (my .hp file grew to 89M, and had millions of samples, and quit with "Out of memory in xmalloc in profile.c") than if I do -i100S (gives me a normal profile). Amanda -- Amanda Clare http://users.aber.ac.uk/ajc99/ Tel: +44 (0)1970 621922 Fax: +44 (0)1970 622455 Dept. of Computer Science, University of Wales, Aberystwyth, SY23 3DB