> > Does it matter if your CPU has "fake" cores via hyperthreading?
> I have a i7-2600 which I believe is 4 cores but shows as 8 in Task Manager. And, I
> can confirm that -j8 is much faster than -j4.
Correct. With enough CPU cores, you quickly end up with a bottleneck on disk I/O when compiling. This is sort of the perfect situation for hyperthreading, because while a given thread is blocked while waiting to either read from or write to the disk, another thread can be swapped in.