Hi, I noticed that by default x86 32 bit builds are targeted for i386 (at least gcc toolset and its derivatives explicitly specify -march=i386 in the command line). Is there a reason to target for such an ancient instruction set by default? Frankly, I'm not sure that the current Boost code would even run on a real 80386, since there are at least quite a few places with atomic operations, which I think were not present on that CPU. Also, I would like to use cpuid safely in my library, and this operation appeared only in some i486 and all Pentiums, so I would basically target my code for Pentium at the very least. But perhaps we could raise the default to Pentium Pro (i686)? Most Linux distributions already switched to this target for 32 bit builds because of availability of cmov instructions. Windows and OS X, I think, don't support older architectures either.