Wrong Opteron 180 CPUID info

[Guest]

Hi,

About 3-4 years ago I got this Opteron 180, used, which I found was not being properly identified by the BIOS and all programs misidentified it for a 280. At the time the guy said there was no problem, and in fact it has worked fine since. Still, this week I decided to see what was the root cause and found that there is a single value wrong returned in register EBX from CPUID function 0x80000001: it returns 0C07h and it should be 0B07h (looking at the correct CPUID for this CPU I found on the net, and AMD specs). CPU markings and all other register values are ok.

Could this be a result of some overcloking? Can it be fixed somehow?

Thanks!

[gshv]

Your Opteron differs from other Opterons by the value in this field:

CPUID Fn0000_0001_EBX LocalApicId, LogicalProcessorCount, CLFlush:
15:8 CLFlush: CLFLUSH size. Specifies the size of a cache line in quadwords flushed by the
CLFLUSH instruction. See “CLFLUSH” in APM3.

I doubt that different CLFLUSH size is the cause of wrong CPU name. A CPU name string on AMD processors is programmed by BIOS when the system starts. I think that your BIOS doesn't support Opteron 180, therefore it incorrectly builds CPU name.

Gennadiy

[Guest]

Thanks Gennadiy!

The value in question, according to the AMD specs, when used to calculate the correct CPU string indicates an Opteron 280. My motherboard is an Asus A8N-E (single CPU socket) so I think it reasonable that there is no such string on the BIOS code. Besides I think that CPU is for Socket 940 and not 939.