I am thinking about getting a new computer and, since it has been a while, I am out of the loop on computer stuff. When I got my last one the dual processors were coming out but not a lot of programs supported them so I skipped it. Now everything is quad core multiprocessors etc and I am kind of clueless. What is the difference between dual core and quad core .. I know one is faster but I honestly don't see too much speed difference on my work machine most of the time. What is all of this stuff though? Thanks

If an application is single-threaded, as Poser is most of the time (except for Poser 7, and only during rendering), then it will only take advantage of one core.  However Poser 7's Firefly renderer, and many bigger applications' render engines, will run on multiple cores, so rendering can be much faster.  Basically the work is divided up into multiple threads, and each of them runs on a separate core (effectively a separate processor really).

For interactive applications, like using Poser in Preview mode (where you do all the setup work before rendering) or pretty much any other desktop-type task like word processing or spreadsheet, you will see little difference, because typically you're waiting on the user rather than on a busy processor.  Going with multiple cores will often be a great benefit when you're doing large, complex renders - typically, for well-designed render engines (which Poser 7, sadly, is not), this means each core = nearly a 100% increase from the base speed 1 core would run the render at.  Some benchmarks:

http://www.extremetech.com/article2/0,1697,2050007,00.asp
http://www.anandtech.com/showdoc.aspx?i=2866&p=13
http://www.hothardware.com/articles/Intel_Core_2_Extreme_QX6700__QuadCore_Assault/?page=10

Ignore game benchmarks, and "CPUMark" statistics, unless you value game performance more highly than render time - they have nothing at all to do with the render benchmarks.  Also look out for the "Cinebench 1CPU" benchmark - because it actually runs in one thread, and only touches one processor, so it's not a very useful statistic when it comes to multi-threaded apps.

Check your product literature to see whether a given product is multi-threaded or not.

Dual core means two CPUs in one package, quad core means four CPUs in one package.

Whether dual/quad core machines perform faster than single core depends on the application. Many applications, e.g. word processors, most games do not make use of the extra cores.

Even if an application can make use of multiple cores/CPUs, it doesn't mean it's dramatically faster on a multicore machine. There are several reasons for this, some hardware based, some software based.

First the hardware reasons: in order to make enough transistors available for a second CPU, some optimization logic had to be sacrificed. The classic Pentium 4 has a lot of runtime optimization on chip - it figures out what instructions should be carried out in what order to get the maximum efficientcy out of the integer and floating point units. The technical terms are "out of order issue" and "out of order completion", the first one meaning that instructions are not necessarily started in the same order as they are fed to the CPU, the second one meaning that some instructions take longer to complete than others, so that an instruction that is issued later may complete earlier.
In dual and quad core processors, the "out of order issue" logic has been removed, which frees up quite a bit of transistors.

So a single core of a multicore CPU might actually be slower than a classic single-core CPU. This was the case with the Pentium D series of CPUs.

Now the software reasons: many applications are simply not designed to take advantage of parallel processing on multiple CPUs/cores. Most games, for example, and most desktop applications too.
Server applications, such as database servers, web servers, etc. will make use of multiple cores, and you can expect a definite speedup.
3D rendering is also an area that profits from multiple cores - at least, in the higher end applications. Newer versions of 3DS Max, Maya, XSI, Lightwave all make use of multiple cores/CPUs when rendering.

Poser 7 is the first Poser version that can use multiple cores. Vue 4.5 Pro, Vue 5 and Vue 6 also make use of multicore rendering engines. The But these applications don't use the extra core(s)/CPU(s) when setting up a scene.

It may be that the newest version(s) of Adobe Photoshop /Adobe CS can make use of multiple cores/CPUs. I don't know.

A definite advantage of multicore/multi CPU machines is the fact that you can have background tasks execute on one core, and use another core for your active application. E.g, you are rendering a Poser 5/6 image, and you will still have a complete CPU available for other work.

The operating system doesn't make too much of a difference. Windows XP Home supports one processor with multiple cores, XP Pro supports two processors, each with multiple cores. Windows Server will support 4 to 32 CPUs, each with multiple cores.

Hope this sheds some light on the issue.

I think I should explain the remark I made about Poser 7's renderer not being too well designed in this sense, as I wasn't really too clear.  

In the case of the higher end renderers, like Mental Ray (3ds Max, Maya), or Vue's engine, rendering is broken up into multiple threads in a very piecemeal way that keeps all cores as busy as possible - which is good, this is what you want.  You press the Render button, and all your cores become very busy - ideally, 100%, but at least they are all doing something as long as the render is running.

In the case of Poser 7, when you press the render button, the task is broken up into 2, 3, or 4 separate sub-tasks, and rendered in a separate thread.  Assume you have a quad core processor, and you've set Poser 7 to render in four threads.  This isn't too great when you have a lot of very complex stuff (e.g. reflection of high quality) in the top left corner of the frame, and much easy stuff on the other three cornders of the frame - what happens is, the easy stuff all finishes very quickly.  The top left corner takes "a long time" because much more math is required to calculate the reflections.  You render is not complete and cannot be saved to file until the whole image is complete.  Meanwhile, 3/4 of your processor capacity sits there doing nothing.  Very annoying, should have been implemented smarter.

If you use Vue6 as well, that does make use of both cores I believe, it certainly uses my HT on my P4!

Hi,

I have a dual core FX 60 running at 2.7 ghz and a new, recently acquired Quad core running at 2.8ghz. Both systems have 4 gig ram and comparable harddrives etc.

I did a speed comparison check yesterday morning on a fairly complex scene that required alot of raytracing. Loaded scene on both systems simultianiously and hit the render button.

The quad core rendered the scene in 25 minutes, the dual core took 1 hour. But I agree Poser 7 use of mutli threading is crap.

So my own conclusion is get as many cores as you can with as much memory as you can and pray that E-frontier will improve Posers multi core handling, or get carrara, it uses all four cores properly and renders a better scene in a quarter of the time.

Peace,

Nick.

Vue 6 definitely uses 4 cores, although it doesn't peg them at 100% in the scenes I've rendered with it (possibly due to using Poser shader tree, I should poke at that some more).

I saw a huge ncrease in rendering speed in P7 when I went dual core as opposed to single. Now when I render anything, I render it with everything on, because I cane, and still get the same render times I had before, with everything off.

BTW just got a base dual core athlon 3800+ system from Tiger Direct Memorial day sale for only $399! It only has a 250 gig hd, and 1 gig or ram, but we'll drop the ram and hd from the wife's older system into it. In com[parison, I got a dual core 5000+ stsyem back in November for mopre then twice the price, $998!!

Plus this new system has xp pro installed NOT vista.. (UGH!)

So here's a question then, in the Genderal Preferences of P7, where it asks how many threads you want to use, does the number of threads correspond to the number of processors you have?

Yep, so for dual core, set it to 2

The render preview takes getting used to... you only see the first core showing up in [preview for some reason, and half way through, BAM! the rest just pops up!

Thanks Gareee, one last question.

Should I enable separate processes to get the most value out this feature then?

Thanks for your help!

Hmmm initially I was going to say yes, but I recall some bug about separate processes, but I can't recall is it was in vanilla P7, or sr1 P7.

If memory serves, separate processes just allows you to get back into P7 to fiddle around while it renders in the background in it's new process, and there is no advantage of doing that for dual core rendering.

The best idea is to set the number of threads to four (even if you only have a dual core). Only reduce it if you encouter memory problems. The reason is the way Poser distributes the image to the processes: it assigns them at the beginning. So if you start with two processes the image will be divided in half and then rendered. Now if the first part takes two hours on one core and the lower part just 30 seconds, you'll have to wait the full two hours. If it's divided in four parts, you may only have to wait one hour. (Of course it could be two hours still, because now one of those left two parts (of the four) still needs two full hours and the other part nearly none.)

hmm interesting.. I'll have to try that, and see if I see any difference.

Hmm any way to display render time for comparison? never bothered to do that b4

Thanks for the info.

script that times renders...
http://www.renderosity.com/mod/forumpro/showthread.php?message_id=2477508&ebot_calc_page#message_2477508

I agree with Dizzi, more threads won't hurt you and will often help you.

edit: well, I'll hedge and say "shouldn't" hurt you.

Louguet does a really excellent job of compiling and publishing a lot of Vue and Poser benchmark information:
http://renderfred.free.fr/p7benchmark.html

And by the way Vue 6, at least with the current update, does bang the crap out of 4 cores with a Poser figure/shader tree loaded. (which is ideal).

hmmm i didnt realise that i will need XP Pro for 2 processors... lucky i find that out now before i start my upgrade....(yes i understand 2 processors and not cores)lol