I've seen a programmers whos programs written in C are slower than i write in PHP ;)
C always was and will be closer to the computer bones and therefore fast. PHP reduces development cost, but it would newer be as fast.
One thing to know language, other thing to know about the "programming". Having a little bit of serious approach to the task planing, complexity estimation and development model you can get some impressive results.
http://chokertraffic.com/
regular 2.4 xeon
2-3 million hits daily served, local response time less than 1 milisecond.
over 1k webmasters
cookie checking, language tracking, complex business logic, dynamic priorities, stats
online statistics and active mirroring
and soon - hitbot protection.
AND THE LOAD ON THE BOX IS 0.00 !!
At times of backup it raises to 0.04. Imagine the power - it hardly uses 1% of system capacity.
System uses FastCGI, C, PHP and MySQL, but what gives the power is a properly implemented in-memory cache.
so my point is:
If you are bad at programming, you would suck with any language.
romans