In this guide we're going to show you how to look up the CPUID, stepping, or sSpec for an Intel processor.
The method is different depending on whether the CPU is already installed or not.
Definitions (in case you're interested)
- Stepping - This is basically the CPU's version number. Whenever Intel improves the manufacturing process, they make a new stepping. Steppings are typically two characters long (like C0, C1, or E0). It's also sometimes called the revision.
- CPUID (CPU IDentification) - This is an identification string (like 1067A) that allows software to find out what features your processor supports (stuff like SSE, MMX, VT-X, etc). All processors from the same stepping have the same CPUID.
- sSpec (specification number) - Unlike CPUID, each stepping of a processor has their own unique 4 or 5 character sSpec string (like SLBBM).
How to get the CPUID and stepping if the CPU is already installed
You can use AIDA64 to get the CPUID and stepping for your processor.
Getting the CPUID with AIDA64
Look in the Motherboard category on the left for the CPUID information. There should be an entry called "CPUID Revision". That's your CPUID (if you remove the 'h' at the end). The h just means it's a hexadecimal number, but that isn't part of the CPUID.
Getting the stepping with AIDA64
The stepping is also located within the Motherboard category, but it's in the CPU subcategory. It should be listed as "CPU Stepping".
How to get the sSpec if the processor hasn't been installed yet
The sSpec is printed on top of the processor and also on the side of the retail box.
As mentioned earlier, the sSpec is 5 characters long (it can be shorter for engineering samples). For example, SLBBM is one of the sSpec for Intel's Xeon E5450.
How to get the CPUID, stepping, or sSpec if you already know one of these
If you already know the CPUID, stepping, or sSpec for your processor, you can use that information to look up the others. If you don't know any of this, you should first use one of the other methods mentioned earlier.
Getting this info for quad core LGA 771 or LGA 775 CPUs
If you have one of these CPUs, you can find the CPUID, stepping, or sSpec on the following page: List of LGA 771 & 775 CPUs. If you have a different processor, scroll down for an alternate method.
Where is the CPUID located on this page?
The CPUID is the same for all processors with the same stepping, so you'll want to look in the CPU steppings table (there's a link to this in the table of contents at the top of the page).
And if you don't know the stepping, look for your CPU's model number in the main CPU table.
For example, if you know your sSpec is SLBBM, just search the page for SLBBM or your Xeon's model number. You'll see the stepping right next to the sSpec in the table. In this case, the stepping is E0. If you then scroll to the CPU steppings table, you'll find the CPUID for that stepping, which is 1067A for the E0 stepping.
Alternate method (for other processors)
You can also usually find this information by searching for your CPU's model number on cpu-world.com (use the "Search site contents" at the top-right).
Here's what we see for the Xeon E5450:
|Core steppings||C0 (Q5YQ, SLANQ)|
E0 (QFUF, SLBBM)
1067A (QFUF, SLBBM)
If you know your sSpec is SLBBM, you can easily tell from this table that your CPUID is 1067A, and your stepping is E0.
Similarly, if you know your CPUID is 1067A, you can tell your sSpec is either QFUF or SLBBM. Engineering samples usually have an sSpec starting with Q, so if you have a normal retail processor, your sSpec is SLBBM.