How does Dual Core work?

[Garry Owen]

Sorry, this may be the dumbest question ever asked but I can't find a
"simple" answer to it. What I do find is a lot of technical
explanations of what it is, which is over my head.

If I want to multitask, say work on a picture in PhotoShop and burn a
CD or DVD at the same time how do I do it? Is there now a step that
one must do to tell the OS to use core 1 for Photoshop and core 2 for
the say Nero? Or does the OS just handle it itself?

If I may, a second question. Most suggestions for RAM I've seen say
that 1GB is now the minimum one should have today. But if one does
buy a Dual Core equipped computer should the RAM be increased to 2GB?

Thanks -- --

 

[General Schvantzkoph]

Sorry, this may be the dumbest question ever asked but I can't find a
"simple" answer to it. What I do find is a lot of technical
explanations of what it is, which is over my head.

If I want to multitask, say work on a picture in PhotoShop and burn a
CD or DVD at the same time how do I do it? Is there now a step that
one must do to tell the OS to use core 1 for Photoshop and core 2 for
the say Nero? Or does the OS just handle it itself?

If I may, a second question. Most suggestions for RAM I've seen say
that 1GB is now the minimum one should have today. But if one does
buy a Dual Core equipped computer should the RAM be increased to 2GB?

Thanks -- --

Dual core means two processors on the same chip. The operating system
takes care of scheduling the tasks on the different processors, the user
doesn't have to do anything special. You need an OS that handles symmetric
multiprocessing, SMP. Linux kernels can be configured to handle different
numbers of processors, 32 is the default for SMP kernels but the parameter
can be changed to handle larger or smaller numbers. For XP I think the
limit is 2 for XP Pro (it could be 4 now), larger numbers of processors
require XP Server (Windoze users can correct me on this, Microsoft can
choose to up the number of processors that they consider reasonable for a
desktop system any time they feel like it, next year when the four core
processors show up they'll have to make the limit at least 4).

As for RAM, the total that you need depends on the number of applications
that you want to run simultaneously and the memory requirements of those
apps. The number of processors is only indirectly related to the memory
requirements. I say indirectly because on a multiprocessor system you are
more likely to want to run more programs at the same time. That said, I'd
recommend 2G for any new system, and I'd buy it as two 1G DIMMs not as
four 512M DIMMs. On a new system you always want to leave room to upgrade
your memory system in the future, buying two DIMMs leaves two sockets free
for a future upgrade.

 

[Bob Knowlden]

XP Home supports one physical CPU socket, so it will run with a dual-core
CPU (like my 4400+). I'm not sure what would happen with a dual-core CPU
that also supported hyperthreading (Intel), if such a CPU exists.

When I first installed the 4400+ in a system that previously held a
single-core A64, XP automatically changed to a multiprocessor HAL. (I say
that as if I really understood what a Hardware Abstraction Layer is.) The
system continued to run reliably, with both cores shown in Device Manager
and with two CPU usage graphs under the Performance tab in Task Manager.
(I've since moved the CPU to a new mainboard, and given it a clean XP Home
installation. It's stable there, too.)

XP Pro supports two sockets, and I believe that it would handle two chips (4
cores). I'm not familiar with the server versions of the OS.


Address scrambled. Replace nkbob with bobkn.

 

[Andrew MacPherson]

XP Home supports one physical CPU socket, so it will
run with a dual-core CPU

I've only recently started contemplating a dual core CPU, and I assumed
this would mean using XP Pro, which adds significantly to the upgrade
cost. I didn't realise it was physical sockets which was the relevant
factor. That's welcome news.

Andrew McP

 

[Bill]

XP Home supports one physical CPU socket, so it will run with a dual-core
CPU (like my 4400+). I'm not sure what would happen with a dual-core CPU
that also supported hyperthreading (Intel), if such a CPU exists.

They do exist.

The Intel Extreme Edition processors models 840 and 955 are dual-core
with hyperthreading, and Windows XP Task Manager shows four CPU graphs.

 

[dawg]

You could save a bit by getting Windows 2000 pro.It's an excellent OS,has
smp support. Downside is MS isn't supporting it anymore. Just in time for
Vista!!

 

[nos1eep]

It is further alleged that on or about Mon, 13 Feb 2006 21:44:29 GMT,
in alt.comp.hardware.amd.x86-64, the queezy keyboard of "dawg" <don't
(e-mail address removed)> spewed the following:

|You could save a bit by getting Windows 2000 pro.It's an excellent OS,has
|smp support. Downside is MS isn't supporting it anymore. Just in time for
|Vista!!

Technically incorrect. Win2K went into 5 year extended support
effective June 30, 2005.

 

[Andrew MacPherson]

You could save a bit by getting Windows 2000 pro

Actually I quite like XP, it's just the extra price hike up to Pro that
was bothering me. I was a late adopter, but I've got very used to the way
it "just works".

Andrew McP