Are high performance C ++ web applications real?

At the moment there is a question about developing a high-performance web application that could withstand millions of hits per day.
Target load of 1000 hits per second and above (up to fill the gigabit channel).

Did any of the readers have experience developing C ++ web applications? I propose to discuss the difficulties and limitations.
It is understood that the application will not have memory leaks (and therefore stability problems), and a 2-3-fold increase in the cost of development compared to PHP is acceptable.

What options do I see:

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For all options: the server processes only dynamic content, all static on individual servers / CDN.

1) fastcgi Apache / nginx module, stores all the necessary information in memory, occasionally dumping critical data in MySQL (well, complex but rare queries can be in MySQL)
2) Apache itself: the application itself handles HTTP requests, using for example the existing implementation in the Poco library
3) To hammer on a C ++ and to make on PHP + APC with data caching inside APC.
4) To score in C ++ and make it in PHP + APC with caching data inside memcached, immediately relying on putting up a bunch of servers.

What opinions?