In non-virtualized Ubuntu 64-bit system (6 Hyperthreaded cores):
Stage start : 0.000
Stage parse : 55.174
Stage syntaxcheck: 0.000
Stage ast : 0.000
Stage optimize : 10.591
Stage mast : 16.263
Stage mbc : 0.179
In non-virtualized Windows 64-bit system (6 Hyperthreaded cores) using Strawberry Perl:
Stage start : 0.000
Stage parse : 55.196
Stage syntaxcheck: 0.000
Stage ast : 0.000
Stage optimize : 9.831
Stage mast : 16.166
Stage mbc : 0.168
It seems build process is using only one core.
Will update with VM times, later.