Subj : Re: what's difference between release and debug compiler in MS vc6.0? To : comp.programming From : Gene Date : Sun Oct 09 2005 08:35 pm One other thing that can be important is that debug links the debug versions of malloc(), where each malloc()'ed block contains a fairly large extra chunk of debugging information. With vc6 I believe it's about 40 bytes. So if you are allocating many small blocks, the debug version of a code can require several _times_ as much memory as the release version. .