The CPUs used in modern computers are called dual-core or quad-core
processors. Why is this a significant change from the previous
generation of CPUs?

"Campino" <(E-Mail Removed)> wrote in message
news:4c2a48fc-7162-4b70-b107-(E-Mail Removed)...
> The CPUs used in modern computers are called dual-core or quad-core
> processors. Why is this a significant change from the previous
> generation of CPUs?

There are also chips that have 6, 8 or 12 cores.

Multi-core chips are equivalent to having that many CPUs in a system, but
such is offered so that all the CPUs (per chip) are on one piece of
silicon.

The largest machine in processing power I've seen is a 48-core machine:
Four 12-core chips, with 256GB of RAM (a minimum cost of about $16k).

On Feb 11, 11:26*am, Jim Beard <jdbe...@patriot.net> wrote:
> On 02/10/2011 06:23 PM, Campino wrote:
>
> > The CPUs used in modern computers are called dual-core or quad-core
> > processors. Why is this a significant change from the previous
> > generation of CPUs?
>
> Making CPUs run faster has become rather difficult and very
> expensive. * *One could simply buy more computers, or put more
> full-fledged CPUs on the motherboard, but this is expensive,
> somewhat inefficient, and impractical for applications that need
> very fast inter-process communication. *One way to make a CPU run
> faster cheaply is to design it as two, four, eight,... CPUs
> (cores) all on the same piece of silicon and let them share the
> workload.
>
> This does not work for everything. *Some things have to be done
> in sequence, and splitting those tasks into multiple processes
> and running them in parallel may not be possible, or practical.
>
> Still, a lot of things can be split up and farmed out to
> different processors with all on the same piece of silicon. *The
> dual-core CPUs today are very good at doing such things, but at
> most you get twice the speed overall (minus a little bit of
> overhead to coordinate use of the cores).
>
> As the core count goes higher, the amount of overhead required to
> parcel out and coordinate tasks becomes increasingly complex, and
> the gain in speed per additional core diminishes.
>
> One can get around the problem of diminishing returns to some
> extent by writing software packages designed to facilitate
> parceling out tasks and running them in parallel, but there is a
> lot of software written before programmers were concerned about
> such things. *So, improvements are being made in how to manage
> tasks on multiple cores and in designing workflow so it can be
> easily parceled out and run on multiple cores simultaneously.
>
> Net result: *Computers keep getting faster and the cost of
> computing keeps going down, faster than would be the case if
> single-core CPUs were all that was available.
>
> Cheers!
>
> jim b.
>
> --
> UNIX is not user unfriendly; it merely
> * * * expects users to be computer-friendly.

Thanks a lot.
That was very good and helpful information.

cheers campino