Processor Speed

• The processing speed is the rate at which a CPU carries out its fundamental operations. The Intel Core 2 Duo desktop processors offer a processing speed range of 1.86 to 3.33GHz. The laptop processors -- also known as mobile processors to differentiate them from their desktop counterparts -- offer a lower range of 1.06 to 3.06GHz. The Core 2 Quad is divided into clock ranges of 2.33 to 3GHz for its desktop CPUs, and 2GHz and 2.26GHz from its two mobile CPUs.
  
  

Front-Side Bus Speed

• The front-side bus speed is the rate at which the processor conducts data transmission with the computer's motherboard by using the front-side bus interface. The Core 2 Duo desktop CPUs offer three FSB speeds at 800, 1,066 and 1,333MHz, while the laptop processor counterpart offers four: 533, 667, 800 and 1,066MHz. The two laptop CPUs that comprise the Core 2 Quad only offer one, 1,066-MHz speed. The desktop version of the 2 Quad omits the 800MHz choice of its 2 Duo counterpart, whittling the FSB speed choices to two: 1,066MHz and 1,333MHz.
  
  

Cache

• Each Core 2 Duo and Core 2 Quad CPU has two caches named Level 1 cache and Level 2 cache. In the event that the processor fails to gain high-speed access to computer data from the L1 cache, it goes to the L2 cache. Intel lists the L2 cache capacities of the Core 2 Duo as 2MB, 3MB, 4MB or 6MB. With the Core 2 Quad, the L2 cache offers 4MB, 6MB, 8MB or 12MB of space.
  
  

Power Consumption

• The Core 2 Duo mobile processors are the most energy efficient of the Dual 2 Core and Quad chips, with a power consumption range of 10 to 35 watts. The mobile processors of the Core 2 Quad have a power consumption rating of 45W instead. Although the desktop CPUs are less energy efficient, the Core 2 Duo versions hold the advantage of the two divisions, with a uniform 65-W rating. Although some Core 2 Quad desktop chips have a 65-W rating as well, others consume as much as 105W.