Core 2 Duo
The majority of the desktop and mobile Core 2 processor variants are Core 2 Duo with two processor cores on a single Merom, Conroe, Allendale, Penryn, or Wolfdale chip. These come in a wide range of performance and power consumption, starting with the relatively slow ultra-low-power Uxxxx (10 W) and low-power Lxxxx (17 W) versions, to the more performance oriented Pxxxx (25 W) and Txxxx (35 W) mobile versions and the Exxxx (65 W) desktop models. The mobile Core 2 Duo processors with an 'S' prefix in the name are produced in a smaller µFC-BGA 956 package, which allows building more compact laptops.
Within each line, a higher number usually refers to a better performance, which depends largely on core and front-side bus clock frequency and amount of second level cache, which are model-specific. Core 2 Duo processors typically use the full L2 cache of 2, 3, 4, or 6 MB available in the specific stepping of the chip, while versions with the amount of cache reduced during manufacturing are sold for the low-end consumer market as Celeron or Pentium Dual-Core processors. Like those processors, some low-end Core 2 Duo models disable features such as Intel Virtualization Technology. Details can be found at the list of Intel Core 2 microprocessors.