Dual Core? How

[rwilkens]

The advertisement for A:M 2007 said it has dual-core support, can someone tell me how to enable it?

 

See:

http://robwilkens.com/tao/notdual.jpg

 

On the left-hand of the attached image, you'll see exercise 2 rendering, on the right side of the screen, you see "Core 1: " and "Core 2: " usage. Core 2 is clearly doing the bulk of the rendering, as it's near 100% usage.. Core 1 is almost sitting idle, so clearly it doesn't appear to be being used.

 

There's got to be some magic trick to enable dual-core support.

 

Do I need to switch to a beta version to get this?

 

-Rob

[Luuk Steitner]

The A:M title bar you show says AM2006. Anyways, the dual core support is only from V14, which is still in alpha at the moment.

[KenH]

Here's the latest v14 that has/will have dual core support. With the TWO cd, you can download and use it.

 

http://www.hash.com/forums/index.php?showtopic=26455&hl=

[Bruce Del Porte]

The dual core support only in V14 Alpha. You can use 100% of both processors with the version you have by running two instances of AM and having each instance render every other frame to a file. You will get a 2X render speed increase.

[rwilkens]

The A:M title bar you show says AM2006. Anyways, the dual core support is only from V14, which is still in alpha at the moment.

 

 

Odd, I have my TinWoodsman cd in the drive, and I downloaded and installed the latest AM2007 upgrade, I believe (unless I downloaded the wrong thing, which is entirely possible). I believe when I ran it it even shows (after I downloaded the previous upgrade) the tin woodsman when i run the program by the a:m logo.

 

However, thanks to KenH for posting the link to v14.0alpha5, I'm installing it now.

 

Ok, It's installed, it's still not using both pseudo-processors fully like I hoped it would be able to, I have an AMD Athlon 64 x2. I might be getting a one second improvement in performance (from 11 seconds to 10 seconds with "LOW" resolution rendering on the can-can animation).

 

14.0 alpha seems to properly detect that I have 2 thread capability -- it just doesn't seem to be using them to the max.

http://robwilkens.com/tao/stillnotdual.jpg

Screenshot above shows the same computer with AM 14.0 alpha 5 rendering the same animation. Note: Core 1 occasionally will shoot "up" to 100%, but then it drops down real quickly.

 

I understand if this is under development, I just want to try to make sure I'm utilizing what I have to the fullest.

 

-Rob

[rickh]

Ok, It's installed, it's still not using both pseudo-processors fully like I hoped it would be able to, I have an AMD Athlon 64 x2. I might be getting a one second improvement in performance (from 11 seconds to 10 seconds with "LOW" resolution rendering on the can-can animation).

 

The dual cores are currently only used for rendering - the A:M interface itself still just runs on a single core. Hopefully as work into V14 continues, we might see more multi-threaded code appearing in A:M.

 

There is also a setting on the Global tab of the options window in A:M that sets the number of threads that you want to use. If "Threads" are set to 1 and Auto is off, then A:M V14 will only use one core at all times.

 

By the way, there is nothing "pseudo" about the current multi-core processors - they physically have two CPU cores and if both are running, the speed does double. The old Pentium 4 processors with Hyperthreading - now that was a genuine pseudo-dual core processor.

 

Richard Harrowell.

[rwilkens]

Ok, It's installed, it's still not using both pseudo-processors fully like I hoped it would be able to, I have an AMD Athlon 64 x2. I might be getting a one second improvement in performance (from 11 seconds to 10 seconds with "LOW" resolution rendering on the can-can animation).

 

The dual cores are currently only used for rendering - the A:M interface itself still just runs on a single core. Hopefully as work into V14 continues, we might see more multi-threaded code appearing in A:M.

 

There is also a setting on the Global tab of the options window in A:M that sets the number of threads that you want to use. If "Threads" are set to 1 and Auto is off, then A:M V14 will only use one core at all times.

 

By the way, there is nothing "pseudo" about the current multi-core processors - they physically have two CPU cores and if both are running, the speed does double. The old Pentium 4 processors with Hyperthreading - now that was a genuine pseudo-dual core processor.

 

Richard Harrowell.

 

Hi Richard,

 

Perhaps I'm a little slow this a.m. -- "A:M interface runs on a single core" -- ok, I sort of understand that -- in other words things like rotating something in a choreography or modeling are single core. But "dual cores are currently only used for rendering" - I thought I was rendering a 2 second animation in that clip I showed in my original message. Do you mean to say that rendering from the _interface_ doesn't use dual core, while rendering externally somehow does.

 

FYI I checked (by accident) before and "Auto" was checked and "Threads" was set to 2 automatically. I tried raising it to 4 and there was no additional CPU usage.

 

I suppose I should mention that I'm running windows Vista and i'm now wondering if there's some sort of 'bias' setting in Vista which targets an application at one particular CPU or another.

 

Thanks for info on dual core vs. hyperthreading. I have 2 dual core systems (AMD Athlon 64 x2 - 3600 or 3800 - not sure, and 4200) and 1 hyperthreading system (P4 HT 3 GHz) -- All systems have 1 GB of ram, though I know now that I'm running Vista I should upgrade eventuallly.

 

One of my dual-cores is running XP instead of Vista (I haven't upgraded it yet). Might it be worth my time to try it out there to see if there's a difference. I'm not sure if I have a good cpu usage monitor there like I have in Vista.

 

Thanks!

Rob

[C-grid]

Hello Rob,

 

I have no experience with v14 version after release 2, from what I have read, I understand that on some systems dual-core should already work.

 

Niels

 

ps.

Rob, if you want to increase the renderspeed, take the 'crab'(mmm, toys/gadgets) of your desktop to lighten the grand-cpu-usage-cycle...

[jlummel]

Hi, thought I'd throw in my 2 cents worth on dual-core and hyperthreading since it's now included in v14. I've read some of the other threads on this in the forums here and think I can add something to the discussion.

 

Hyper-threading is done on a single CPU core under the assumption that each instruction uses only part of the CPU. So you can run multiple instructions at the same time IF each instruction uses a different part of the CPU. Parts of a CPU include the Floating Point Math Unit (FPU), Arithmetic and Logic Unit (ALU, it does integer math and logic functions), the Memory Controller, Register Operator, etc. So if you have one thread that executes a lot of ALU instructions and another thread that accesses memory or does FPU functions mostly, both threads can run at the same time and the work gets done in 1/2 the time.

 

However, if both threads execute the same type of instructions they have to wait for each other to finish before they can execute. These thread collisions waste time because as there is time spent handling the threading and waiting (and is why multi-threaded rendering on a hyperthreaded system is so much slower that a single thread).

 

When A:M renders it uses the same type of instructions in each thread, so hyper-threading is much much slower. Now if you wanted to browse the Internet while rendering in A:M, then hyper-threading would most likely allow you to do that without slowing down the rendering too much because web browsing places a different load on the CPU than rendering does.

 

With 2 physical cores you don't run into this problem since each CPU is free to execute it's assigned thread independently of each other.

 

I would seem to me (though I haven't checked this out) that if you are running a Pentium D with 2 cores and Hyperthreading support that disabling hyperthreading should speed up rendering in A:M since these CPUs look like 4 cores to WinXP. In reality you only have 2 cores and 2 hyperthreads, which could lead to the thread collisions in each of the cores. I doubt that either WinXP or A:M knows which 2 of the processors are actually virtual hyperthreads and which are real CPU cores. Turning off hyperthreading would give you 2 CPUs in WinXP (or Vista), which would always give you the higher rendering speed.

 

I'm interested in seeing what the effects of using a Pentium D with HT disabled is, as well as a comparision to the Core Duo systems. I never run AMD CPUs for Windows applications (though I used them excusively for Unix applications), so I'm not at interested in AMD specs, but would like to see the Intel ones if anyone has run them.

 

I'm also interested in how well A:M runs in Vista multi-core, compared to WinXP.

 

PS- think they'll come out with AMD based Macs? Or have they already? OSX is NextStep, which is a Unix OS!

[rickh]

Perhaps I'm a little slow this a.m. -- "A:M interface runs on a single core" -- ok, I sort of understand that -- in other words things like rotating something in a choreography or modeling are single core. But "dual cores are currently only used for rendering" - I thought I was rendering a 2 second animation in that clip I showed in my original message. Do you mean to say that rendering from the _interface_ doesn't use dual core, while rendering externally somehow does.

 

I didn't see your previous post when I sent my last reply, so I didn't know that you have tried V14.

 

A render to disk from the A:M interface in V14 can use dual core rendering.

 

Your photo puzzles me a bit - I would expect both cores to be camped on 100% almost continuously. The snapshot shows you are in the middle of rendering patches so A:M would be asking for maximum power and neither core is near 100% ! . If this is Vista running on an AMD dual core PC, then obviously some application, service or the operating system is robbing A:M of full CPU cycles.

 

If this is the Hyperthreaded Pentium 4 we are seeing, the the display is showing the Pentium 4 is running at full speed. Core 1 + Core2 = 105% which is about the absolute maximum a Hyperthreaded Pentium 4 could do.

 

By the way, if you have XP on one of your systems, why would you want change it to Vista? XP will be more stable for years at least. There is nothing in Vista that can help A:M run any faster then it can in XP.

 

I would definitely try this test out on the AMD dual core with the Xp on it. To see the CPU usage graphs, just run Task Manager. It would not surprise me if the AMD 4200 rendered at about 4 times the speed of the Pentium 4.

 

Also remember that 14 Alpha means Alpha. V14 probably still has a lot of refinement before it is ready for the production release. That probably includes work on the dual core support.

 

Richard Harrowell.