Anyone know how to "max out" CPU time when fluid baking?

I noticed today when baking fluid, that Blender only uses 1 CPU for baking (see screenshot). It’s running on a Quad 6600 so it would be nice to take advantage of all 4 CPUs.

Does anyone know how to force blender to use all CPU power to bake fluids?



see this post

So it’s not possible? Okay well that kinda sucks.

At least I know now. Thanks Willington :slight_smile:

is this a free gadget and where can you get it ?
nice to see cpu and memory usage

That’s just the Gnome-System-Monitor, it comes with Gnome.
On windows, there is the Task Manager, run it by either RMB on the Taskbar>Task Manager, or run ‘taskmgr’.

@redbyte: You can compile Blender with OpenMP, giving it support for multicore fluids, but you need to use the pro version of MSVC, which costs some money, which is why the devs don’t include it in official releases. Just search for “blender with openmp” for more information.

Which version of Blender are you running? (Bake Indicator is blocking the version number).

I’ve gotten multi-core support running on both 2.47 and 2.48 when baking fluids.
Linux 64 bit and Q9450.

One of the developers mentioned that if you compiled using icc (Intel’s compiler) that you may get better results since it supports OpenMP perhaps a bit better.

Other than that, from what I gather it’s pretty much under the software’s control.
Though, I’ ve experimented a bit, and it seemed that it performed better for some fluid simulation setups than others.

It also seemed that the System Monitor had a slight effect on the reported CPU History result.
If you look at the midpoint of the chart in image4 below, you can see a slight improvement when I increased the sampling time from 1 to 5 seconds. So perhaps using a terminal based monitoring app. may provide you with more accurate data.

For a simple icosphere fluid drop, core usage was approx. 50%, and for a larger simulation with a rotating cube I was getting about 75 to 80% core usage.


On Windows XP I notice that fluid baking uses all 4 of my CPUs.

Sorry but I’m a little bit slow at this kind of stuff. What exactly is an “intel compiler”? Is it hard to do?

Your screenshots look promising. You wouldn’t by any chance be able to explain the steps you took to get it working like that would you?

Oh and I’m using Blender 2.48 on Ubuntu 8.04 64-bit

Oh you’ve got to be kidding me. I just made the switch to Linux for this exact purpose! The ability to render insane amounts of fluid on screen without windows crashing. Which I can now do, but I have to wait 4 times as long for the fluid to bake? I can’t win! :o

The scene I’m trying to render looks like this:
Thousands of droplets everywhere!

So anything above 25% CPU time would be a big plus :slight_smile:

Thanks again! :eyebrowlift:

PS. Has anyone noticed how ridiculously slow it is when using the new “Fluid Controls”? No joke it baked 2 frames over a 3 hour period. TWO FRAMES. As soon as the fluid control was switched off again it baked an entire 200 frames in under 10 minutes. Wild.

Actually, there’s not much to explain. It just ran.

I’ve just started using Ubuntu 64 about a month ago, so I’m still learning the ropes.
It may be that since I have compiled Blender, that my system has some dependencies
installed that your system doesn’t; but I’m not 100% sure.

Your best bet is to maybe try a build from Graphicall:

CubOfJudahsLion Oct-14-08 build

A compiler is just a program that turns the raw source code into an executable program that you can run on your system.

I pretty much followed oxigen’s instructions on building Blender with scons at:

It was pretty easy to follow. To get multi-threading, when you compile I just replaced the line:

Rajiv Mudgal has alot of helpful advice here (esp. the command ‘sudo apt-get build-dep blender’)
This looks for all the required dependencies ahead of time, instead of you having to go find out what you need each time you get an error because something is missing.

Hope that helps.