So, does anyone know an effective method to ultra-compress files? You might have seen some PC games compressed to incredibly small sizes here and there (like GTA San Andreas which was compressed to 1mb file!). I tried many high-compression programs like 7zip, UHARC, KGB Archiver, but I can't get the same results on other types of files, like a music album for example. Why some files can't be compressed? I don't get why games can be reduced to 70% of their size, but a 60MB album, or a 5MB PDF are pretty much the same after compression.