Twin dual core XEON reports 8 CPUs on 64bit kernel

[Paul Oppenheim]

it's "hyperthreading".

If you type `cat /proc/cpuinfo` you will get a lot of info. In that info 
is "core ID" - if two entries have the same core ID, they are two thread 
units on the same core.

Hyperthreading is also known as SMT. There is a lot on the web about it!
 From Sun's marketing team:
http://www.sun.com/processors/throughput/faqs.html#5

You do NOT want to disable this in BIOS, you will see a performance 
penalty if you do. Linux knows what to do with SMT since kernel ... 
2.6.9 IIRC?

+ paul

Bruce Ferrell wrote:
> Anyone know why this is?
> 
> uname -a says 2.6.15-26-amd64-server
> 
> DISTRIB_ID=Ubuntu
> DISTRIB_RELEASE=6.06
> DISTRIB_CODENAME=dapper
> DISTRIB_DESCRIPTION="Ubuntu 6.06.1 LTS"
> 
>