Multi-threaded particle system on mac


I’m pretty sure the particle system is supposed to be multi-threaded, seeing as the mac version comes bundled with a script to “set_simulation_threads”. I’m currently working on a smoke scene, so the particle system has to be baked for that, but I’m thinking the smoke sim baking should be able to make use of multiple threads too?

My problem is, blender is only using one thread to bake both, no matter what setting I use in the script (yup, I’ve restarted blender after setting the amount).

I’m using a build fresh off of the Blender build bot from a couple of days ago (45497).

Am I wrong in thinking that the number of simulation threads is used for baking?


my particles dont even use a full core

I can confirm, on osx simulations don’t go beyond the use of only one cpu, even if compiled with OpenMP and even if they seem to use more threads, the sum of power doesn’t exceed that of one single thread, so in a quad core you have maximum 1/8 of computational power.
I already said it on several posts, but never got a single word about the matter, some sort of omertà in this regard.

So I’m glad you posed the question and I’ll look here for some clarifications.


Do you see?..


To be fair, a particle system simulation might be such that it isn’t easily split among multiple CPUs or processes anyhow. If every one of them needs constant access to the same data-structures, it would be difficult to split the work meaningfully apart. (How would you do that “by committee?”)

What i find totally unacceptable from my user point of view, and which I previously remarked in other threads, is that cloth or smoke or fluid sims not only are so slow, but though these tasks take only a fraction of the cpu power, less than 1/8 in my case, blender becomes absolutely irresponsive to any imput, and often looses the use of keyboard and/or mouse, just like not only sims were not multithreading at all, but even blender itself can’t manage such situations.
This is a very big problem that hampers any serious use of simulations, because the only remedy to such behaviour is a force quit, so it’s not a matter of waiting more or less but of using it or not (not!).


That does sound like a ticket that needs to be opened with somebody somewhere …

sundialsvc4, I don’t understand what you mean, sorry for my bad English :frowning:

(EDIT:maybe a request for assistance?)

if you mean to open a bug report, I’m not the right person to correctly understand and describe the matter. (EDIT: and I think that everybody could confirm that, am I wrong?)

I have to add that in my experience i find Particles and Hair quite fast and fluent instead.
(quad i7 intel 64 bit, 16 GB RAM , os x 10.7.5)


This is how this software seems to work and it seems pretty pathetic, I have a 2012 12 core mac pro with 24 threads and it sits there for ages to render a single frame on a one object, one camera, one lamp render with 2 modifiers placed on the object. It’s fairly quick until I place a subsurface modifier up to: Views 4; Render 4. This is an utter joke, it’s the same thing I had with my previous mac that was a 2008 mac pro with 8 cores and no multi-threading. I have seen no performance improvement despite having a machine with 2 to 3x the performance of the previous. In-fact I don’t really notice much improvement compared to a dual G5 …

My machine idles at 5% CPU usage, I have 10GB’s of RAM free, what’s the point having these powerful machines if no-one can write software that actually uses any of the power… I might as well have stayed with a G5 as far as blender is concerned. I use AE whenever possible, and when I need to do any 3D modelling in blender I dread it…

I have found nothing on any forum that gives any answers to these issues, quite a few questions asked, but I never see any answers, certainly no answers that actually answer the problem.

So what is the deal with this?? does anyone actually know, or is every blender developer ignoring this because they don’t want to admit the software is deficient??? I fail to see how people have produced any decent work with this software, I can only assume there is some elusive answer lost in the complexity of the software interface, that I still find completely user unfriendly and far to over complicated, it’s so unlike any other application to make it an application you can really make use of unless your using it everyday… though I’ve persisted with it as so many people insist it’s the best one to learn once you get use to it… well I can’t get used to watching a £3000 computer sit idling for no fathomable reason.

Any light on this subject from any being in this universe would be much appreciated, sorry I am not able to give any light to the person who created this thread, but you really are not alone…

I also use a MAC (Imac27" late 2009 16 gig). I got the MAC right before I started using Blender. The first thing I found was that the Imac is not a good 3d work station. I love it for my Adobe suite, but it blows with Blender. Now, 3 years later, Blender is my primary tool and I am about to get a new computer. I was thinking of a new maxed out Macbook pro. But for the reason you have mentioned as well as others, I am starting to think in a different direction. I am pretty sure the Adobe CS6 collection can be converted to Windows for free, so that is the direction I am headed right now.

I feel your pain. My solution is to abandon Apple. Not a great solution, but it does solve the problem. I moved to apple from Windows years ago because at the time Apple was the best tool for my graphics work, time passes and things change. Apple is no longer the best computer for my tools…

For multithreaded simulations you could try

Place57, Richard Marklew,
as expected, yours are the only kind of answers we are able to get, sort of ‘Change your PC’ or ‘don’t use multithreads’, very pitiful.


I do not disagree that it is pitiful, but it is what it is. Since for what ever reason, the Mac version of the software does not do what I want, and I need it to do what I want for my job, I have three options:

  1. Hire (fund the project) someone to code it right.
  2. Move to a platform that does work the way I need it to.
  3. Do nothing and just complain about how it is.

I can’t afford to fund it, and I don’t have time to complain, so I will probably be moving to a different platform. I don’t like the solution, but I can deal with it.

please, could you explain to me what makes the mac so inadequate to blender multitasking?
I too am on imac i7, and I’m interested to the matter, my question is not at all polemic .

Anyway I hope you agree with me that the issue is not just a personal problem, and that for the sake of blender something should be done.

Thank you, paolo

I completely agree it is not a personal problem. I believe (and I may be wrong) the reason falls on development and funding. There are limited funds for Blender development. The blender foundation has to look at what is the best way to spend their money. Unfortunately you and I are using a Mac, which is not the machine most people use with Blender. If more people (I believe there are only about 240 people supporting Blender with their funding) started funding Blender then they might look into some of these issues.

Until the, it is our ox that gets gored.

Sadly, this sounds utterly correct, thank you place57.


Huh? I also use a Mac !! Cycles GPU rendering, all in some dream for me.

For fluid baking I’m getting 4 cores running each at 70% and 4 more running about 20% each. Whatever you use is your decision and whatever that happens to be you have to make the most of it and stop feeling sorry for yourself.

(just making the post long enough)


Very sad!
I made a try with r54010 and a quite complex cloth sim was very responsive, I thought the issue was gone.

Are you on mac platform too?
Because if it were not so, and if the problem was general, that would be a definite plus toward the resolution of the problem, a really serious one, that can actually make simulations unusable.


What is wrong with you guys!!! Come on now, Richard-Marklew gave a suggestion for fixing the threading problem on the Mac OSx, and you criticize his response without even reading it, and keep wallowing in your self pity. If you are not trolls, take his advice and report on whether it worked for you or did not work. He then comes back and explains that he has 4 cores working at 70 percent on his Mac and you continue to ignore him. What is wrong with you???