Geoff Chappell - Software Analyst
The required argument consists of whatever follows immediately within the same command-line token.
The argument is formally numeric. Values greater than 2000 are coerced to 100, with a warning (D4014).
The /Zm option overrides earlier instances of itself (and is overridden by later instances).
The number is a scaling factor, expressed as a percentage, for the sizes of various memory allocations sought by (and, in one case, for) the front-end C and C++ compilers.
For instance, the memory block that CL passes to the front-end compilers (via their -zm option) is ordinarily 50MB, but becomes 50MB times number percent if /Zm is given.