Yup, all those things are useful, but they don't solve everything. I've worked on projects where a single change to a header file would lead to a 20-minute rebuild adventure and where individual .cc files would take 10 minutes to compile. Caching and distcc build farms help somewhat but there's still, fundamentally, the critical path of a single file's (re)compilation, and only a faster CPU will help with that.

(And if you say "thin client, distcc, big build farm", then you just need the latest CPUs in the build farm instead.)

Of course this is as much an argument for a real module system in C/C++ as anything else...

(And, I completely agree that TSX and other architectural stuff is totally awesome, too. Perhaps that'll drive adoption more than incremental perf, but I'm just arguing perf is still often really important.)