Hi, Vitali and I are using FASTMEM in a subroutine and it works well in flat mode. However, trying to run the same test in cache mode is causing problems (issues with not enough memory) at runtime (not compilation). !DIR$ ATTRIBUTES FASTMEM :: var A turnaround for the moment is to enclose that between an if defined declaration like this: !DEC$ IF DEFINED(name) !DIR$ ATTRIBUTES FASTMEM :: var !DEC$ ENDIF and then compile with the variable ‘name'. Marta