Just to came it clear: The "turbo" mode is not new, Intel uses it in Penryn processors for better single-threaded application performance over 65nm Core 2, just most end users don't remember the early hype about it. It's called Intel Dynamic Acceleration Technology:
http://apcmag.com/intel_announces_co...erclocking.htm
http://www.intel.com/technology/arch...whitepaper.pdf

That's why what you see in a single thread is not strictly "xGHz" performance at all.