Re: [dmidecode] Detecting dual-core processor

[Jean Delvare]

Giulio,

On Mon, 12 Feb 2007 14:09:11 +0100, Jean Delvare wrote:
> On Thu, 19 Oct 2006 12:47:54 +0200, Giulio Orsero wrote:
> > Linux 2.4
> > 
> > How, if possible, to detect whether the running processor is a dual-core one
> > using dmidecode?  
> 
> The processor information in the DMI table relates to the physical
> processors, and there is no flag to differenciate multi-core ones.
> There is a flag to tell whether a processor supports hyper-threading
> though.
> 
> You may use the processor family and/or signature, if these are
> properly filled, to find out whether the processor is a multi-core one,
> but you'll have to compare the values with the manufacturer
> documentation by yourself.

I have to update what I wrote here. As of SMBIOS 2.5, the entry type 4
(Processor Information) has additional fields to store the number of
cores and threads of the CPU. The upcoming version 2.9 of dmidecode
decodes these fields. For example:

Processor Information
        Socket Designation: Proc 1
        Type: Central Processor
        Family: Opteron
        Manufacturer: AMD
        ID: 12 0F 04 00 FF FB 8B 17
        Signature: Family 15, Model 65, Stepping 2
        (...)
        Core Count: 2
        Core Enabled: 2
        Thread Count: 2

Of course dmidecode can only display the information if the BIOS has
filled these fields in the first place, which means that the BIOS must
be recent enough.

-- 
Jean Delvare