[ubuntu-uk] Do I have a quad-core netbook (surely not?!)

[J Fernyhough]

On 28 June 2011 13:21, Ross Mounce <ross.mounce at gmail.com> wrote:
> Dear list,
<snip>
> I believe the processor is a dual core Atom
> N550 http://ark.intel.com/Product.aspx?id=50154
> Two questions: A) Why does it show as 4 processors? Are these all real? Have
> I somehow 'unlocked' another couple *hopes*?

It's a dual-core processor with hyper-threading, appearing to the OS
as having four cores. Two are real, two are "virtual". The design came
in with the P4, in essence it tries to interleave instructions so the
core is used more efficiently.

>                        B) If it's just 4 threads, can I optimally run 4
> separate instances of a 32-bit program one each on each thread/core without
> losing overall efficiency? (The program I have in mind is a bit
> technical/obscure, and no, it doesn't have a 64-bit version)

You shouldn't lose any efficiency - otherwise Intel wouldn't have
added it. :) It basically tricks the OS into doing basic
multithreading so the program doesn't have to.

Jonathon