If you understand and have a working knowledge of C++ and you will be doing you own code maintenance -- use C++ its the fastest language around today.

The problem with C++ is the availability of good programmers and existing scripts to work with.

Quote:

[H]ipHop for PHP. With HipHop we've reduced the CPU usage on our Web servers on average by about fifty percent, depending on the page. Less CPU means fewer servers, which means less overhead. ... ...HipHop for PHP isn't technically a compiler itself. Rather it is a source code transformer. HipHop programmatically transforms your PHP source code into highly optimized C++ and then uses g++ to compile it. HipHop executes the source code in a semantically equivalent manner and sacrifices some rarely used features ? such as eval() ? in exchange for improved performance. HipHop includes a code transformer, a reimplementation of PHP's runtime system, and a rewrite of many common PHP Extensions to take advantage of these performance optimizations. Scaling PHP as a Scripting Language PHP's roots are those of a scripting language, like Perl, Python, and Ruby, all of which have major benefits in terms of programmer productivity and the ability to iterate quickly on products. This is compared to more traditional compiled languages like C++ and interpreted languages like Java. On the other hand, scripting languages are known to generally be less efficient when it comes to CPU and memory usage. Because of this, it's been challenging to scale Facebook to over 400 billion PHP-based page views every month. ... https://developers.facebook.com/blog...hp--move-fast/

This is a platform worth watching, maybe learning -- it recognizes the issues and offers a possible solution.