Re: Wrong CPU being shown by the BIOS
- From: ipleb <plebism@xxxxxxxxx>
- Date: Thu, 2 Oct 2008 02:44:21 -0700 (PDT)
On 30 Sep, 22:29, Paul <nos...@xxxxxxxxxx> wrote:
On Sep 29, 8:49 pm, Paul <nos...@xxxxxxxxxx> wrote:
On Sep 29, 1:32 pm, "Dave" <no...@xxxxxxxxx> wrote:Just for chuckles, (assuming you get it running again), why not run the
"ipleb" <pleb...@xxxxxxxxx> wrote in messageHmmmmm
Hi allYes, the BIOS makes a guess as to what CPU is installed based in part on
I have an Asus P5N motherboard with an Intel Core 2 Duo E4300 1.86ghz
Socket 775 FSB800 CPU. All was working fine ... until recently when I
installed an extra gig of RAM which put the system total at 3gig - the
PC runs Vista home pre.
Now I am not sure if installing the RAM did this or messing about in
the OC settings of the bios, but everytime the PC boots it halts at
the BIOS screen with a message sayinh.
"Unknown CPU detected, install latest BIOS to unleash Power"
Now I have the latest BIOS installed but the problem seems to be that
the CPU is coming up as an Intel Xeon 4...@xxx ghz, 2 CPUs detected..
Vista also shows that an XEON is installed
Can anyone think why this has happened?
clock frequency and multiplier, along with other settings you might "tweak"
when you are overclocking. Apparently, in messing around with the OC
settings, you have stumbled upon settings that closely match the specs of a
Do you know how I could work out what the original settings the actual
CPU would be?
Intel Processor Identification Utility.
(Supported processors list)http://www.intel.com/support/processors/tools/piu/sb/cs-015472.htm
That utility should be using the ideas in this document. Intel
provides assembler and C code identification sequences, for their
processors. BIOS designers are supposed to incorporate these
ideas, as part of the BIOS design.
"AP-485 Intel Processor Identification and the CPUID Instruction"http://www.intel.com/assets/pdf/appnote/241618.pdf
Processor identification is also addressed here, in the thousands
of pages of docs.
As an example, the Xeon X3220 and the Q6600, are suspected to be
very similar. They're both LGA775, and overclockers have tried
both of them in desktop boards.
Here is an X3220 -
And here, a Q6600 -
So while the basic CPUID info looks the same, the Intel utility
can still tell the difference. There must be a secondary indicator
somewhere, that is giving it away. And it won't be solely frequency
- the multiplier and multiplier range prevent overclocking from
hiding the identity completely. (I'm not sure if BSEL is
protected and available inside the processor or not - BSEL
are the pins on the processor, that announce the nominal
So I'd be curious what the Intel Utility (and perhaps CPUZ) think.
Hi there Paul
I have run that app and it is still reporting an Intel XEON
Intel(R) Processor Identification Utility
Time Stamp: 2008/09/30 14:30:26
Number of processors in system: 1
Current processor: #1
Cores per processor: 2
Disabled cores per processor: 0
Processor Name: Intel(R) Xeon(R) CPU 4812 @ 1.60GHz
Maximum CPUID Level: A
L1 Instruction Cache: 2 x 32 KB
L1 Data Cache: 2 x 32 KB
L2 Cache: 2 MB
Enhanced Halt State: No
Execute Disable Bit: Yes
Hyper-Threading Technology: No
Intel(R) 64 Architecture: Yes
Intel(R) Virtualization Technology: Yes
Expected Processor Frequency: 1.60 GHz
Reported Processor Frequency: 1.60 GHz
Expected System Bus Frequency: 800 MHz
Reported System Bus Frequency: 800 MHz
This data doesn't help me out much :-(
There is a field in the "Branding String" with
provision for indicating a Xeon. The above doesn't provide
the raw data from the processor, to see whether that is
what is being returned.
One thing that concerns me, is "Revision: 0". That means
the processor is not getting a microcode patch installed
by the BIOS. It implies that the BIOS is not fully set up
to support E4300. The BIOS really doesn't know what processor
I would check the BIOS version installed. If you go here, you
can see what version is needed for your board. Enter the
model number, like P5N-D, and see what minimum BIOS version
The other possibility is an internal processor failure, but
only a failure in the branding information seems highly
The Intel utility identification of Intel(R) Xeon(R) CPU 4812 @ 1.60GHz
is also bogus, as I tried looking on processorfinder.intel.com
and there is no X4812 that I could find. So even the Intel
utility is being fooled by something. But exactly
what, I cannot tell you.
I checked the pinout on Xeon LGA775 and Core2 LGA775 socket,
and they seem to be identical. I was thinking that perhaps
the processor wasn't making good contact with the socket,
but that doesn't appear to be a possible cause, as the pinouts
are identical. So either something is screwed up inside the
processor itself, or the BIOS has a hand in this. I would not
expect a clear CMOS to make a difference, as I don't recall
a place in the CMOS RAM structure, to store processor info.
That normally gets stored (somewhere) in DMI/ESCD. It has
to be stored, so the BIOS can detect a processor change, if
Your Intel processor should be provided with a warranty from
Intel. Perhaps an Intel tech support person could comment
on whether they've heard of this before or not - a change
in ID info. You would think, that at least the Intel PIU
utility would get the ID right, unless the info coming
from the processor, really is screwed up.
Hi Paul - thanks for your comments - I have also tried a small app
called CPUID - this gave the following data:
it tells me I am running an Intel Xeon 5110 - a socket 771 lga package
- weird as my mobo is obviously a socket 775
The core speed is at 1600 with a multiplyer of x8.0 bus speed at
200mhz and a rated FSB of 800mhz
I have two ddr2 533 pc2 4300 1gig chips and two ddr2 533 pc2 4300
512mb chips to give a total of 3gigs
The DRAM freq is at 266/7 and the max bandwidth of each chip is
Does that shed any light?
It is definately the right bios update, and I can't remember whether
the problem started post bios update or post ram install
Finally - if the PC boots ok and run ok and all seems good - in real
terms does it actually make a difference that it is showing as an XEON
cpu and not a Core 2Duo ???
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