How many cores does blender support?

Hiya, I plan on buying a mac pro, not a macbook pro, but a mac pro… it comes with a whooping 8 cores.

What I want to know is, how many cores can blender use? some programs only use a few cores, but if blender can use all 8, why I would nearly faint from having 8 cores render beautiful waterscapes and such.

Thanks for the info peeps!

Blender’s renderer can use up to 8. If you want to use multi core fluid simulations, you have to use a special compilation.

Well, blender swaps back and forth between my two cores. (But only using one at a time). But hay, that may just be a promotion, and is easily changed. And hay, it’s OSS, so if you want it, it’s always possible to get it. (even if you have to pay someone $3,000 to make it, an obvious over exaggeration, I think).

WOW, 8 cores. Who need that! WOW, that’s a LOT! (for now anyway)

If I’m not mistaken it can use 16 threads. However, since I am mistaken, it can only use 8 threads.

Depends on which part of blender you are referring to, and which particular compilation you are using. Some sections of code are multi-threaded and some aren’t. But then again the only areas that really need it are things like rendering and baking. Supposedly the code is being set up to utilize OpenMP, but I don’t know what has become of that. OpenMP allows for some dynamic multi-threading at compile time, but I don’t know if that’s been done or not. The compiler has to support it. Recent versions of GCC and ICC support it, but the free versions of the VisualStudio compiler don’t.

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@spiffandy: you do know about the “threads” field in the render buttons, don’t you?
I only have 2 cores, but setting threads to 2 when rendering, definitely uses both.
(…except on composite renders)

Andy, think about upgrading the video card to the NVidia 8800. I have the stock ATI 2600 HD and it seems to be much slower in rendering than I think it should. I know there have been a lot of posts here about ATI’s crummy OpenGL support and their bad drivers. I need to do a bit of research and see if there’s anyway to speed this baby up. For everything else though this monster screams.

Not to rain on your parade, but Blender doesn’t use any hardware acceleration in rendering. Getting a better graphics card will only improve your performance in editing. Sorry. :frowning:

“Only” 8 cores? So there’s no reason to dream of a quad core, quad cpu machine?

Are there any plans to expand beyond 8 cores?

I’m quite happy with my quadcore.

I’d imagine that >8 core support eventually will be there. Until then, there won’t be really >8 core machines… :slight_smile:


Just change BLENDER_MAX_THREADS from 8 to i.e. 32 in file BLI_threads.h.
I’ve just did a test and I can set 32 threads, but I have only 4 cores machine so it’s little bit slower than 4 threads :wink:
But you will have to learn how to build your own blender. I think it’s worth of trying because you can set best processor flags for your machine, and of course change number of max threads :wink:

The internal code is not at all places ready for that increase. Your mileage may vary.


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Probably you’re right. I will need more testing. But for now it works well.

hmm… looks like this thread is pretty popular for discussion.

I shall have to look into it. To answer whoever asked about the >8 cores, I think a dual quad is the max for now, but I won’t be surprised when a 16, or a 32 core pops out.

And yeah, I was talking about baking and rendering. Also, Major Tom, can you switch video cards fairly easily or no?

When Intel’s Nehalem comes out, we may need 12 threads (6 cores, hyperthreaded) or 16 threads (8 cores, hyperthreaded)… or maybe even more?

Has anyone run Blender on any really big mainframe machines, i.e. hundreds or thousands of threads? I know it would have to be on a machine with real shared memory, and not a cluster…

… although built-in support for clustered renders in standard Blender would be cool. I’d probably use it via Amazon’s Elastic Compute Cloud.

Isn’t it just cheaper to use a renderfarm and buy a modest (2-4 cores) system instead?

Here, i use Blender with 8 cores for render. Few things in blender will not act like multithreaded, but it’s not so relevant since i often have 3 different Blender files open and have stuff done fluently. Blender 1 will Render for few hours non-stop and cores indicator shows as the 8 would be activ at 70%. Blender 2 will also start a render and see here all together works still pretty and the indicator shows cores to work only at around 90%! But the best is: Blender 3 is on, and i work hard on it… still no crash, only the render of blender 1 takes a tiny longer par frame. I can still open Photoshop and send a picture to my website with Dreamweaver, open Safari to get on the forum…
Really 8 cores is fun! And Blender takes a serious good overall profit of it! :wink:

Andy, yes it’s fairly easy to change video cards in your MacPro, if you can swap out a RAM chip, you can swap a video card. The biggest problem is the lack of choices for those cards. Because the Mac market is so small (compared to Windows), the vendors don’t port all their cards over to OSX, just a select few. The next big problem is that the drivers for those cards are not always optimized or debugged well (usually just an issue with ATI cards).

One good thing about the MacPro cards however, is that they are good, higher end cards. Apple’s finally been able to get some decent cards for their towers, after a long dry spell. All of the video cards for the MacPro have dual video-out ports too, so you can run two monitors on one card - adding to the sweetness. Barefeets has some good reviews on all of the current cards.

Luckily, with all of the newer Intel Macs you have the ability to run Windows natively using Apple’s BootCamp software - or through the Parallels virtualization software. Any modern Windows video card will run in your MacPro when booted into Windows - it just won’t be recognized in OSX. The plan for my MacPro is to throw another Hard Drive in it, partition it for XP and maybe Ubuntu, and do some tests with those OS’s as well.

Depends on how heavy the stuff you’re rendering is. Before you can send a scene to the render farm, you have to set it up and tweak it out. The faster you can render, the better.

Right MajorTom, GC is still the weak part of Apple… It’s about changing since the market shares rise. I’m having the original NVIDIA GeForce 7300 GT in mine… not that it “sucks” but i can feel the limits yet. I’ll keep it till a real good offer comes around… and fitting in a MacPro rev1…