It could be due to debug symbols being embedded into the binary after compilation; This space is too small to explain this, but either there would/should be a ./configure flag that tells the build system to build it with debug symbols, or a step that invokes the ‘strip’ program somehow, or a compiler/linker flag that would tell it to build with debug info ‘external’ (to create a separate symbol file). Debug symbols are usually large, because they contain names (in human-readable form) of every function, variable and whatnot. They are needed if you need to actually debug the program for gdb (or your choice of debugger) to show you pretty names rather than addresses in the binary. Some /not all/ are needed if the program is a dynamically loadable module, so that the dynamic linker can actually have a clue what to call is where in the binary. Therefore the step to strip the built binary is usually performed by the build system, because calling ‘strip’ on a ready binary can damage it beyond repair. So much for theory 