[ubuntu-uk] Dual-Core = less not more?

[Kris Douglas]

On 27/12/2007, Kris Douglas <webbox.uk at gmail.com> wrote:
>
>
>
> On 26/12/2007, Ian Pascoe <softy.lofty.ilp at btinternet.com> wrote:
> >
> >  Matt
> >
> > I'm surprised that a dual processor machine came with only 1 Gb of RAM -
> > I thought it was more common these days to ship with 1 Gb of Ram per
> > processor.
> >
> > However, the differences between multi core and multi processor are
> > rather ambiguous as depending on the manufacturer they can mean the same
> > thing!  Generally speaking multi core processors share the same DIN whereas
> > multi processors each have their own seperate socket.
> >
> > But, as long as things work, thats great - just bear in mind what Chris
> > says about the fact that unless you are running multiple processes / apps,
> > you won't generally see much of a difference in performance in apps, as,
> > referring back to a pre Xmas posting, very few apps on Linux are multi
> > threading yet.
> >
> > HTH
> >
> > E
> >
> > -----Original Message-----
> > *From:* ubuntu-uk-bounces at lists.ubuntu.com [mailto:
> > ubuntu-uk-bounces at lists.ubuntu.com]*On Behalf Of *Kris Douglas
> > *Sent:* 26 December 2007 18:44
> > *To:* British Ubuntu Talk
> > *Subject:* Re: [ubuntu-uk] Dual-Core = less not more?
> >
> >
> >
> > On 26/12/2007, Matthew Macdonald-Wallace <matthew at truthisfreedom.org.uk>
> > wrote:
> > >
> > > Hi all,
> > >
> > > I was one of the many who purchased the Dell laptops when they shipped
> > > here in the UK with Ubuntu pre-installed.  I've got a Pentium
> > > Dual-Core
> > > chip (not a core-duo although I'm not sure what the difference is!)
> > > installed and although /proc/cpuinfo shows both cores as seperate
> > > processors, I'm really not convinced that the dual-core with 1024MB
> > > RAM
> > > is faster than my old 1.4GHz with 512MB RAM.
> > >
> > > I've got stock Gutsy installed on the laptop (upgraded from feisty
> > > using
> > > apt-get dist-upgrade) so if there are any packages that you think
> > > would
> > > be more beneficial, please let me know.
> > >
> > > One of the things I've stumbled upon in the forums is the possibility
> > > of
> > > running x64 on Core2-Duo processors - would that help me here?
> > >
> > > Cheers,
> > >
> > > Matt.
> > >
> > >
> > > --
> > > ubuntu-uk at lists.ubuntu.com
> > > https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk
> > > https://wiki.kubuntu.org/UKTeam/
> > >
> >
> > I think there is a point where the performance just levels out. You will
> > notice the difference when you run lots of apps at once. I dont know, but
> > I'm running X86 on a 2x dual xeon machine with 8gb of ram, and it boots
> > about the same time as my dual core 3.6ghz 2gb ram, but is much better
> > on performance, when running say, lots of applications, database stuff etc..
> >
> > --
> > Kris Douglas
> >       Softdel Limited Hosting Services
> >
> >       Web: www.softdel.net
> >       Mail: kris at softdel.net
> >
> >
> > --
> > ubuntu-uk at lists.ubuntu.com
> > https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk
> > https://wiki.kubuntu.org/UKTeam/
> >
> >
> Just referring to windows here, you can assign processes specific
> positions on CPU's can't you, I think it's actually set as the Affinity,
> like cpu0,1,2,3,4 depending on your configuration. Is this not possible with
> Ubuntu/ The Linux Kernel?
>
> Just wondering, normally Linux has something ahead of windows when it
> comes to this sort of thing..
>
> To put it into practice, say you had a dual CPU 200mhz server, running
> Apache and Postgres/ MySQL (whatever you prefer) on the one chip makes it
> run slowly... So you can set the affinity of the SQL server to cpu1 only
> (the second cpu) and have the Apache server only running on cpu0. This in
> theory would allow the apps to have 200mhz of CPU each... I imagine that's
> how it works in Win, so what about Linux? Anyone?
>
> --
> Kris Douglas
>       Softdel Limited Hosting Services
>
>       Web: www.softdel.net
>       Mail: kris at softdel.net
>

For Reading, research lead me to see:

http://www.cyberciti.biz/tips/setting-processor-affinity-certain-task-or-process.html

http://ubuntuforums.org/showthread.php?t=636521

-- 
Kris Douglas
      Softdel Limited Hosting Services

      Web: www.softdel.net
      Mail: kris at softdel.net
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