This may be off-topic, as it concerns using gprof on an HP-UX system for a program compiled with HP's native aCC (using the -G option, which is documented as compatible with gprof). I get this every time I run gprof on even a small sample gmon.out: $ gprof <binary> gmon.out > gprof.out gprof: out of memory allocating 4294967256 bytes after a total of 15552512 bytes This works on other HPs we have in house, though I don't have access to them to be able to track down why. Any clues that might point me in the right direction? 4,294,967,256 seems like an awful lot of memory to handle a 8,647,174 byte gmon.out file.... Thanks! MR