Intel® Xeon® Processor
Identifying Your Processor

What are package types?
Need Help Finding Your sSpec Number?

This page is designed to help interpret the markings on an Intel® Xeon® processor, and to explain some of the tools available for determining the stepping, voltage, and features of a particular Intel® Xeon® processor. The primary tools that will help identify a Intel Xeon processor are the Intel® Processor Frequency ID Utility, the Specification Update, and the Product Specifications and Comparisons tool.

Xeon Processor
Production (sSpec)
Sample Mark
Group A Line 1
Group A Line 2
Intel® Xeon® processor
Legal Mark
Group B Line 1
Group B Line 2
ATPO mark
SN mark
8 Character String
4 digit String
Group C Line 1
Group C Line 2
Group C Line 3
Product Code
Sxxxx (country of origin)
FPO-SN mark
sSpec 20-23 Character string
sSpec Assembly Site
13 Character String

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Bottom View

Note DP identifies the processor as an Intel Xeon processor for uni or dual processing and MP identifies the processor as an Intel Xeon processor MP for 4way or 8way processing.See What is the difference between Intel® Xeon® processors and Intel Xeon processors MP? for a comparison of these processors.

The Intel® Processor Identification Utility was developed by Intel Corporation to enable consumers with the ability to identify and in some circumstances determine if their Intel processor is operating at the rated frequency intended by Intel Corporation. Beginning with the Pentium III processor, the Intel Processor Frequency ID Utility has the capability to provide actual and intended frequency, or speed, information.

The Specification Update and is a resource, which contains information about the different steppings and versions of processors. If you need information about the voltage, thermal specifications, the processor packaging, or other information about a particular Intel Xeon processor, you'll need to view the part numbers on your processor and compare that with the Specification Update.

The Specification Update is a document that has more complete information, but the Product Specifications and Comparisons tool is a web-based tool that may be a bit easier to use.

Need help finding your sSpec number?

The sSpec number is also known as specification number. It is a five character string (SL36W, XL2XL, etc.) that is printed on the processor, and used to identify the processor. You can find this number by looking at the markings on the processor (see Figure 2), or on the label that came with your boxed processor. See Figure 1 below for an example of how to read the label to find your sSpec number.

Figure 1: Finding the sSpec number on the boxed processor label

boxed processor label

Figure 2: Finding the sSpec number in the processor markings
sSpec number in the processor markings

This applies to:

Intel® Xeon® Processor

Solution ID: CS-017377
Last Modified: 23-Oct-2014
Date Created: 23-Nov-2004
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