The terms on Intel Processor

Boxed Processor An Intel® boxed processor is sometimes referred to as a retail box. The boxed processor comes in a sealed box with a 3-year warranty from Intel.
Bus/Core Ratio The ratio of the system bus speed and the operating (core) frequency of the processor. This information is needed by most motherboards when setting up the BIOS for a new processor.
Bus Speed The speed of the bus that connects the processor to main memory (RAM). As processors have become faster and faster, the system bus has become one of the chief bottlenecks in modern PCs. Some examples of bus speeds are 1066 MHz, 800 MHz, and 533 MHz.
Core Stepping Throughout the life of a processor life cycle, the processor may go through several steppings or versions. Newer steppings typically have some type of improvement over previous steppings of the processor. Steppings can be identified by the CPUID String.
Core Speed The speed at which the processor executes instructions. Every processor contains an internal clock that regulates the rate at which instructions are executed. It is expressed in Megahertz (MHz), which is 1 million cycles per second or Gigahertz (GHz), which is 1 billion cycles per second.
CPUID String A four character string that can be used to identify the features of the processor. The first character is typically a 0 and the second and third characters represent the family and model number. The fourth character represents the processor stepping. For example, if you find one processor with a CPUID String of 0672 and a second processor with a CPUID String of 0673, both processors have the same family and model number of 67, but with different steppings. This sometimes has an "h" at the end of it to denote hexadecimal notation.
ECC Short for Error-Correcting Code, it is an algorithm used with special circuitry for testing the accuracy of data as it passes in and out of memory or cache.
L2 Cache Size The size of 2nd level cache. L2 Cache is ultra-fast memory that buffers information being transferred between the processor and the slower RAM in an attempt to speed these types of transfers.
L2 Cache Speed The speed of the 2nd level cache. Since all current Intel® processors have internal L2 cache, the cache speed will be expressed in MHz/GHz or the speed in relationship to the processor core speed. For example, the Pentium® II processor and some early Pentium III processors had the L2 cache run at half the processor speed, while newer Pentium III processors and Pentium 4 processors have their cache run at the full speed of the processor.
L3 Cache Size The size of 3rd level cache. L3 Cache is ultra-fast memory that buffers information being transferred between the processor and the slower RAM in an attempt to speed these types of transfers.
L3 Cache Speed The speed of the 3rd level cache. The cache speed will be expressed in MHz/GHz or the speed in relationship to the processor core speed.
Manufacturing Technology The size and spacing of the processor's transistors (silicon etchings), which partially determine the switching speed. The diameter of transistors is measured in microns. One micron is one-millionth of a meter.
Mixed Stepping When running systems with more than one processor, the processors must be compatible with each other to function. The processors must be the same family of processor (Pentium® 4 processor, Pentium D processor, etc), the Cache Size and Cache Speed must be the same, and the Core Steppings must be compatible with each other. If you are using two or more processors with different steppings, this is known as mixed steppings.
OEM Processor An Original Equipment Manufacturer (OEM) processor, sometimes referred as a tray processor, is a processor that is sold to an OEM manufacturer or distributor intended for installation. The warranty varies in length and is provided by the place of purchase.
Package Type The physical packaging or form factor (size, shape, number and layout of the pins or contacts) in which the processor is manufactured. There are many different package types for Intel® processors. See the Processor Package Type Guide for photos and details.
PCG The PCG marking on the processor and processor box is used by Intel and third party board and component vendors as a common method to describe processor power requirements. PCG does not promise compatibility, but is an indication of processor electrical requirements. In addition to PCG requirements, processors have board support requirements such as chipset, BIOS, and pin considerations that can determine processor-board compatibility. Intel recommends that you contact your motherboard manufacturer to obtain a supported processor list when selecting a processor for your motherboard.
Processor Number Intel® processor numbers allow you to quickly differentiate among processors within a product family and make more informed decisions. Processor numbers are based on a variety of features that may include the processor's underlying architecture, cache, front side bus, clock speed, power and other Intel technologies that enhance your experience.
Product Order Code The actual part number used in ordering the processor from an Intel distributor. (example: BX80526H1000256) sSpec Number Also known as specification number. A five character string (SL7AA, SL8VN, etc.) that is printed on the processor, and used to identify the processor. By knowing the processor's sSpec Number, you can find out the processor's core speed, cache size and speed, core voltage, maximum operating temperature and so on.
Supported Features This is a broad category of processor features that includes Intel® technologies as well as other notable features of the processor such as Dual Core, or Execute Disable Bit. The purpose of this category is to makes the more important features searchable via a filter. It is not meant to be an all-inclusive category that encompasses every processor feature.
Thermal Design Power (Also referred to as Thermal Guideline) The maximum amount of heat which a thermal solution must be able to dissipate from the processor so that the processor will operate under normal operating conditions.
Thermal Specification The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader. For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor™s automatic mode is used to indicate that the maximum TJ has been reached.
VID Voltage Range The voltage range set by the VID signals as a reference to the VR output voltage to be delivered to the processor Vcc pins. For more details, please refer to the relevant processor specification document.