Specification (S-Spec) number

Specification number, or S-spec number, is a five character code that uniquely identifies such CPU characteristics as core frequency, bus frequency, the size of level 2 cache, thermal design power, and so on. Specification numbers always start from letter 'S' and are usually printed on the top of the CPU. Intel Pentium, Pentium MMX and Celeron processors in plastic PPGA package have specification numbers printed on the bottom of the CPU. To find out processor characteristics from the specification number please use "Search by S-Spec" form on this page. We also recommend to use Intel processorfinder tool.

Some examples of specification numbers: SX409, SL8VR, SL9S5

NOTE: Intel engineering and qualification samples are marked with specification numbers that start from 'Q' - these are so called QDF numbers, and they are used to identify qualification and engineering samples.