Power Management and Turbo Mode:
Intel is also introducing new "Power Gates" with the Nehalem micro-architecture. In addition to reducing leakage power, Power Gates allow idle cores to enter a deep sleep state (C6) while other cores may be under load. Core i7 processors also feature integrated power sensors and an integrated Power Control Unit that allows the processor to perform real-time monitoring of each core's current, power, and voltage states. One of the reasons why having onboard power controllers and an integrated Power Control Unit is integral to the Core i7 is that it enables the CPU to divert power from idle cores to active cores in what Intel calls "Turbo Mode." If a particular core is being heavily taxed, it can tap into some of the power that would ordinarily be used to for one of the other cores if it is not currently in use.  Turbo Mode typically increases performance of a single core, or the entire CPU by one speed bin; a 3.2GHz Core i7 processor with a stock multiplier of 24, for example, will operate with a multiplier of 25 when in Turbo Mode.  Through overclocking, however, these parameters can be changed, and Turbo Mode could result in further speed increases.

Above we have a die shot of Nehalem with each

of its major sections labeled. As you can see,

the memory controller resides along the top edge

of the die, with miscellaneous I/O and QPI links

along either edge. The four executions cores are

lined up through the middle, with a instruction

queue in between, and the shared L3 cache below. 

 

With the new Core i7 processors,

Intel is also introducing a new

1366 pin socket. The new LGA 1366 socket looks and functions much like the current 

LGA 775 socket for Core 2 processors,

but it is slightly larger. Pictured above is an LGA 1366 socket open without a CPU, and closed with a Core i7 CPU installed. Also note, the mounting holes for the CPU cooler are further apart than an LGA 775 socket. More on that later.