On Wed, Jul 15, 2009 at 3:37 PM, Igor R <boost.lists@gmail.com> wrote:

> Yes, it is limited in that it does not support a couple of other flags
> simultaneously.
> However, if you think about it, /MP is a replacement of /Gm (Incremental
> Build) and /Yc (Precompiled Headers).

IMHO, it's much more disappointing that /MP has almost no effect with
/LTCG (and /GL). With these switches no much work is done in "compile"
time - actual compilation occurs in the link-time, in one single
process.

/MP is most valuable to the preprocessor, especially when using Boost in your project. When you use boost in almost every single file, on a very powerful machine you could still end up waiting 1-3 seconds for each file to compile. This is, of course, subject to what part(s) of boost you're using. In short, I think /MP introduces extreme performance improvements at most, and no benefit at all at least. It might not be perfect, but it's a very good first step for Microsoft.