cpu vs render

chrisw · Post by **chrisw** » Thu Dec 18, 2008 5:59 am

hi i was rendring a new toon but noticed my new faster computer seemed to take longer?? and looking at my quad core cpu load use.. it appred to be using only one cpu?? i have a q6600 intel quad core its four processers at 2.4g each my old cpu was a e8400 wich was a dual core at 3.2g so am i to gather that as5pro will only use a single core therefor my older dual core will render faster?

moorsel · Post by **moorsel** » Thu Dec 18, 2008 6:54 am

As far as I know, the rendering in AS is single threaded. This implies only one core is used for rendering. If the processing speed of this core is less than the processing speed of one core in your old system, it could very well be that the rendering is slower.

I think this is a generic issue, not only related to AS. Software must be designed to take advantage of multiple cores for delevering a higher througput on multi core systems. This typically means it has to distribute its load over multiple threads, threads run if parallel in you have multiple cores and/or processor and by doing so more work in the same timeslice can be done. Whenever the software is not multithreaded, it will not distribute its wokrload over the available cores/processort and therefore isn't able to take advantage of multiple cores/processors.

heyvern · Post by **heyvern** » Thu Dec 18, 2008 7:25 am

I think you can open multiple instances of AS and assign each one to a core. Then render frame ranges in each instance.

-vern

mkelley · Post by **mkelley** » Thu Dec 18, 2008 3:37 pm

Good call, Vern.

I just tried this with one of my dual core fast machines that always rendered slower (apparently) than my "standard" machine and, sure enough, it cut render times in half (just like you'd expect it would) compared to doing the entire file with the same machine.

A bit of a PITA to setup and manage, but nice to know it can be done in a pinch (for me the 2D rendering of AS is lightning fast compared to my experience in the 3D world -- heck, I don't even feel the need to put more than one machine from our rendering farm at work on AS most times. But if Mike wants to bring AS into the production world network rendering should be in the pipeline somewhere).

Post by **Lost Marble** » Thu Dec 18, 2008 11:46 pm

Vern's suggestion is correct, and until we get multi-threaded rendering in the app it will work. Here's a way to maybe improve it: You can render from the command line, which will reduce some of the user interface overhead and will be a little bit faster. It may also be a cleaner way to render multiple, simultaneous frame ranges. More info here:

viewtopic.php?t=1318

mkelley · Post by **mkelley** » Fri Dec 19, 2008 3:49 am

Mike,

Unfortunately that command line render does not allow you to choose CPU and I'm guessing the process to do so will be more cumbersome than just running multiple instances of AS. Also, as you note, those of us in Windows don't have a progress bar.

I hope you get a chance to look at this whole issue for future releases. In particular I'd like to see batch export improved so that it can recognize an external list of files as well as file date/timestamps (so it would only rerender files that have changed since the last rendering, for example). As someone who has come from a 3D background, network rendering is of prime import to me and while the 2D rendering is so much faster I would be in seventh heaven if I had some of the same tools available to me in AS (I've thought about writing some of my own tools, and perhaps in conjunction with your command line rendering I could, but at my age I'm much more interested in animating than programming :>)

NetGenSuperstar · Post by **NetGenSuperstar** » Fri Dec 19, 2008 5:00 am

mkelley wrote:Unfortunately that command line render does not allow you to choose CPU and I'm guessing the process to do so will be more cumbersome than just running multiple instances of AS.

Actually, if you simply run two instances from the command line, your operating system (Windows, I'm guessing) will automatically split the load between the two cores. This is the concept behind the render farm application that I'm working on; it basically renders as many scenes as you have servers, CPUs and cores, and lets the server handle the rest. For now, this is the best solution.

moorsel · Post by **moorsel** » Fri Dec 19, 2008 6:55 am

Unfortunately that command line render does not allow you to choose CPU and I'm guessing the process to do so will be more cumbersome than just running multiple instances of AS. Also, as you note, those of us in Windows don't have a progress bar.

If you are using Windows, there is no difference in "choosing the processor" between the command line and interactive version of AS. By default Windows assigns a process to all CPUs available but you can change the CPU affinity of a certain proces (and by doing so you tell windows to use a specific (set of) cpus for the selected proces). This can be done in task manager, choose the tab processes and select the process. Right click on the process and select the affinity option from the menu. There you can change the CPU affinity of a process. Don't know if there is some kind off (free) batch utility that can do the same.

Darramouss · Post by **Darramouss** » Sat Dec 20, 2008 7:49 am

I sooooo can't wait for ASP to make use of multiple cores. I hate it when a render is taking forever and I've got 7 spare cores sitting there, doing nothing!!

As a suggestion, Mike, (and we all know there's been no shortage of those!!!), it would be great if you could specify the number of cores you wish to dedicate to a render, the same way that Blender does. That way people with 2, 4 or 8 cores could ensure that they have enough processing power to manage non-ASP render related tasks.