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CPU stepping problem

Steinar Skjelanger
Occasional Visitor

CPU stepping problem


I get the application popup error with event id 41 in the Windows 2003 system log of one of our DL380-G3 servers:

"The CPUs in this multiprocessor system are not all the same revision level. To use all processors the operating system restricts
itself to the features of the least capable processor in the system. Should problems occur with this system, contact the CPU
manufacturer to see if this mix of processors is supported."

There are two 3,2GHz CPUs in the server. Surveyor reports 4 cpus (due to HyperThreading, I guess), all with "x86 Family 15 Model 2 Stepping 5". I have tried installing the latest ROMPaq, but it didn't help.

I.e: The server was purchased with two CPUs, they are reported as being equal but somehow Windows sees them as different. Is there a way to verify they really are equal, and if so convince Windows to see it that way too?
Tarek Kawach
Honored Contributor

Re: CPU stepping problem

Hi Steinar:

This message is usally informational.
Make sure that the firmware is uptodate on the server. and try to swap the processors.
- Intel has a utility that you can download to check the stepping on the processors. Usually the lowest stepping should be first.
Boot Strap loading issues.
- This server only holds 2 CPUs - try to turn off the hyperthreading in the Bios. that will make windows only see 2 CPUs.

- With the latest Bios Firmware from HP this server dose support mixed processors steppings.

- This error message is informational and will not effect your server performance at all.

Here is an advisory from HP that might help you.

ProLiant Server With Mixed CPU Stepping Levels May Generate An Event ID 41 Message in Microsoft Windows 2000 Operating System
customer notice CN0315W revision 0
released February 2004

Event ID 41 with mismatched CPU stepping levels in Windows Server 2003 and in Windows 2000;en-us;227438
Article ID : 227438
Last Review : April 12, 2005
Revision : 4.1

Best regards,

Hey, look a light at the end of the tunnel.
Steinar Skjelanger
Occasional Visitor

Re: CPU stepping problem


I used the Intel Processor Identification Utility you mentioned ( which found a difference in Level3 Cache (cpu #1 reports 2 MB, while cpu #2 reports only 1 MB). Everything else was equal.

Even though the server should be able to use CPUs with different steppings, I don't like the fact that it's complaining about it when the CPUs are supposed to be identical. I suspect it might be some kind of hardware error, so I have submitted a support request with the details from the Intel utility.


Steinar Skjelanger
Szabolcs Petho_1
Regular Advisor

Re: CPU stepping problem


Just an information. With PSP 7.20 at System Management Homepage you can check the stepping: home->system->system board

We have similar "problem" but have lucky and found pair of processors with same stepping in different boxes. So we changed the processors... Anyway when Intel dual processor motherboards started to spread, I remember it was highly suggested to use same stepping.

I thought HP and other big brands had high price standard processors since they bought and stored processors with same stepping to later system upgrades... So what is the truth? ;)

Regards, Szabolcs
Tarek Kawach
Honored Contributor

Re: CPU stepping problem

Latest Server Firmware for HP Servers and new G2, G3 and G4 servers all have support for different steppings of processors.

HP has different pdf files docs on this subject.

Since you can buy a server with one processor and later possible add the 2nd one; there is no way that the stepping will be the same unless you bought the processors at the same time.

This will be a cpu boot strap issue that the o/s will look for. As far as I know this error is informational and there is no effect on the server performance.
Mixed processor steppings are supported within the same family of processor. ProLiant servers provide support for new processor steppings by adding the required microcode to the ProLiant System ROM. If the System ROM does not contain the required microcode, the server will halt with an error during the Power-On Self-Test (POST), indicating that a System ROM upgrade is required
Processor and Chipset/Memory
Q1. What kinds of processors are supported on ML370 G4?
A1. ML370 G4 supports the latest Intel Xeon DP Processors. The supported processors are Intel Xeon 3.2GHz and higher speeds. The processor is based on Intel Pentium 4 architecture with the NetBurst micro-architecture and hyper-threading technology. HP supports mixing of processor stepping in the system for a dual processor system. However, mixing of processor speeds is not supported in this box.

Hey, look a light at the end of the tunnel.