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Mixing X5472 issue

RH3
Beginner
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Hello everyone, first post,

T7400 Vista Business BIOS A11

started life with one X5472 processor.

I wanted to put in a 2nd.

Found an identical, or what I thought, X5472

Both ARE x5472 3.00 1600 12mb. SLASA

The original chip on CPU-Z has a stepping of 6 and rev of CO

The "new" chip has stepping of A and Rev of EO

Now I've read that this is most likely the issue.

Most interestingly, this machine was never using all 4 cores of the first chip! I finally got it to recognize all 4 cores. I noticed this by using CPU-z for the first time and seeing 2 core 2 thread. So got that fixed. Very strange, any thoughts on why that would have not been using all 4 cores for however long?

Both chips will boot and load by themselves and shows all 4 cores and will run fine. I did this to make sure the new chip was good.

I can get the machine to boot and load with both chips installed, if some parameters are just right. However it won't recognize the 2nd chip for usefulness. The parameters I'm speaking of are, msconfig-boot-advanced-"processors" clicked and detect HAL checked.

What I mean by that is, it will show on the BIOS it will show in the device manager as 8 "processors" but it won't recognize in CPU-Z. or cinebech or anything like that.

I was just told by someone that only specific Revs can be used for multi processor machines....even if they match. Is this accurate? Somehow I don't think so, but I COULD be wrong.

Anyway. It's taking me two days of getting my buttkicked to get, nowhere.

That being said, my goal was to increase the speed of this machine for video editing and After effects. By getting it to run all 4 cores, I have accomplished that. But now I really don't know where to go.

I do want to upgrade to win7, if that matters.

I'll stop rambling here. Thanks for reading and hope I can get some responses from people who are clearly good at modifying things that aren't necessarily supposed to work that way. thumb.gif

Ryan

edit found this on Intel 5400 mixing processors data sheet...

Mixing processors of different steppings but the same model (as per CPUID instruction) is

supported.

So yeah..I'm stuck.

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Amy_C_Intel
Employee
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Hello, 2ndAmend:

In order to make this configuration work, both processors need to have the same step. You can have two processors with step C0 or two processors with step E0. See here for the step ordering and spec information http://ark.intel.com/products/34447/Intel-Xeon-Processor-X5472-12M-Cache-3_00-GHz-1600-MHz-FSB# @ordering Intel® Xeon® Processor X5472 (12M Cache, 3.00 GHz, 1600 MHz FSB) Specifications.

Regards,

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RH3
Beginner
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Amy, thank you for the response. If that is the case then why does the Intel documentation state that mixing steps is OK?

i'm not trying to be difficult just trying to understand the discrepancies I'm finding. And is an OS issue or a BIOS issue?

Ryan.

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Amy_C_Intel
Employee
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Sure, I understand.

 

Where can I find the documentation that you are referring to?

Regards,

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RH3
Beginner
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http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/quad-core-xeon-5400-datasheet.pdf http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/quad-core-xeon-5400-datasheet.pdf

page 26

found this on Intel 5400 mixing processors data sheet...

Mixing processors of different steppings but the same model (as per CPUID instruction) is

supported.

Just as I quoted in the original

And is it a BIOS issue or OS issue?

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Amy_C_Intel
Employee
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Thank you for the reference.

 

 

2ndAmend, could you please confirm your motherboard model?

Regards,

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RH3
Beginner
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Truthfully, I don't know.

Its a stock Dell T7400 machine. CPU-z lists Dell. ORW199

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Amy_C_Intel
Employee
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At this stage I would recommend checking with Dell if you current motherboard firmware supports these two stepping codes. One of these codes is being read and other is being ignored this could be related to fact that one of the processor is newer than the other therefore is not being recognized; however, this should be fixed if the firmware supports the newer stepping code instead of the old one, if the firmware only recognizes the old one there is no possible way to recognize the two of them(new and old). In summary, the firmware must support the newer stepping code in order to have both fully recognized.

Regards,

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RH3
Beginner
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Well, I did some more testing and everything works on Linux.

All 8 cores run full 100%.

Without this knowledge I would agree with your assumption.

 

So based upon this, its not the CPUs, the motherboard, the bios the firmware or anything in that, it's most definitely the OS.

Which is a major major issue with Windows. I don't know if you work for Intel or not, but I think that this should be a fixed by Windows. A patch developed and released.

 

This is a widely talked about issue on many computer forums, and people who do not go the distance I have blame the CPUs. It is NOT your chip, they work fine together it is the OS causing the issue.

 

I also tried Overclockers Linux based stress testing software and it worked perfectly on that as well, generating 6100 primes per second, which is pretty respectable for these vintage processors.

Let me know if I can offer any documentation to help with this, but I'm betting it won't go any further than this thread.

Ryan.

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