multi-core processors (core2duo, core2quad, phenom)

mrbug · 2008-06-16 16:58:50

How does Linux (in general) handle multi-core processors? I've read that in the Windows world, programs must be written to use more than one core/processor.

Do you need to recompile programs with architecture-specific makepkg.conf settings (march, mtune, j) to be able to use the extra cores?

Finally, is there a good reason to get a tri or quad core processor over a dual core processor? Would a 3.0 ghz dual outperform a 2.4 ghz quad?

Last edited by mrbug (2008-06-16 17:00:09)

schivmeister · 2008-06-16 17:40:58

All applications have to be written to support multi-threading; SMP; multi-core. The norm now for Linux/Unix apps is to build in support for it, and it will be utilised if the hardware is capable. For instance, sometime ago, the SMP option in the kernel wasn't included by default.

Linux, in fact, handles SMP better than Windows. This is especially true due to superior CPU scheduling and process synchronisation. However, some apps are still lacking the support, eg. some multimedia encoders.

As mentioned, most binaries will be compiled with SMP support when available. If it's a special case, it won't be hard to find some notes. The job server is to thread the compilation jobs, starting at -j3 for dual-core (number of cores + 1).

Depending on your needs, you may benefit from all those cores. However, jumping from 2 to 4 or 8 or 1000 doesn't really add up to that much value for the buck unless you have mission-critical systems.

mrbug · 2008-06-16 18:01:18

Regarding Linux being better with SMP than Windows, that's what I thought... and it's good news for me.

I do a fair amount of multimedia encoding/decoding. I want to get back into 3D modelling/rendering (with Blender). I also like to listen to music while using the computer, and it's really annoying when the sound skips out for a second because Firefox is forking or Java is loading.

Would you suggest that I go for a higher speed dual over the lower speed quad then? I think that the quad would be more "future-proof," but I don't know if I like the idea of the individual core speed being lower than my current (single) processor speed.

moljac024 · 2008-06-16 18:31:11

mrbug wrote:

Regarding Linux being better with SMP than Windows, that's what I thought... and it's good news for me.
I do a fair amount of multimedia encoding/decoding. I want to get back into 3D modelling/rendering (with Blender). I also like to listen to music while using the computer, and it's really annoying when the sound skips out for a second because Firefox is forking or Java is loading.
Would you suggest that I go for a higher speed dual over the lower speed quad then? I think that the quad would be more "future-proof," but I don't know if I like the idea of the individual core speed being lower than my current (single) processor speed.

Well, in the future applications will more effectively use more processors, so I'd go with the Quad-Core...
Dual-core also seems fine (I've got dual core in both my desktop and laptop)

The single core speeds of dual-core processors today are lower than the single processors speed before them, but they seem to be better, don't they ?

Last edited by moljac024 (2008-06-16 18:32:02)

mrbug · 2008-06-16 18:42:01

The single core speeds of dual-core processors today are lower than the single processors speed before them, but they seem to be better, don't they ?

That makes a LOT of sense.

I'm planning on keeping this computer for as long as possible -- my old computer before this broken one was around for about eight years. I think that I will go with the quad, especially since speeds will have increased by the time I can buy all of the parts at once.

Thanks! (to all)

moljac024 · 2008-06-16 18:47:07

But the focus should be on developing more optimized programs and better programming languages (garbage collection,anyone? ) instead of making CPUs so fast that programmers can get lazy.

mrbug · 2008-06-16 18:54:17

I agree with that completely! That's one of the reasons why I actively discourage the adoption of Vista -- the gains (slightly UNIX-like permissions) are far outweighed by the wasteful eyecandy.

In my opinion, the purpose of having multiple threads/processors and more memory is to be able to run more programs/daemons/whatever at once, not just accommodate more intensive versions of older programs.

....but then again, I use fluxbox, finch, newsbeuter, screen, and ssh more than anything else.

schivmeister · 2008-06-17 14:52:22

3D rendering would really benefit; quad-core would be perfect.

Last edited by schivmeister (2008-06-17 14:52:49)

Arch Linux

#1 2008-06-16 16:58:50

multi-core processors (core2duo, core2quad, phenom)

#2 2008-06-16 17:40:58

Re: multi-core processors (core2duo, core2quad, phenom)

#3 2008-06-16 18:01:18

Re: multi-core processors (core2duo, core2quad, phenom)

#4 2008-06-16 18:31:11

Re: multi-core processors (core2duo, core2quad, phenom)

#5 2008-06-16 18:42:01

Re: multi-core processors (core2duo, core2quad, phenom)

#6 2008-06-16 18:47:07

Re: multi-core processors (core2duo, core2quad, phenom)

#7 2008-06-16 18:54:17

Re: multi-core processors (core2duo, core2quad, phenom)

#8 2008-06-17 14:52:22

Re: multi-core processors (core2duo, core2quad, phenom)

Board footer