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An Open Letter to Tim Cook


On the same day that Jens Verwiebe decided to stop maintining the OS X binaries for Blender because of Apple's bad GPU support (don't worry, someone else has stepped in), the LuxRender team published an open letter to Apple CEO about the state of their support.

Paolo Ciccone writes:

We have found out that the OpenCL GPU drivers for OS X are broken and are unable to render but the simplest of scenes. With anything barely complex the driver simpy crash. CPU rendering works fine.

This is not a problem of the GPU or even the software expertise of AMD or nVidia. It’s a mater of old drivers shipped with OS X. The same scenes with the same exact hardware render on Windows and even on Linux. Beautifully. This is because, on those other OSes, it’s possible to update the drivers independently. On OS X OpenCL is part of the OS and the drivers can only be updated by Apple. Apparently OpenCL is not at the same level of priority than providing new Emoji and so we are stuck with broken drivers.

We have tried to work with AMD (they are powerless in this) and even talked with some Apple engineers, but nothing happened.

So today I decided to email Tim Cook, the CEO of Apple, directly, because we can’t continue like this. Here is the text of my email:

Read the letter here.

Ton Roosendaal threw in his support too:

What is your take on this? Is Apple making it harder to do your creative work on their platform?

About the Author

Bart Veldhuizen

I have a LONG history with Blender - I wrote some of the earliest Blender tutorials, worked for Not a Number and helped run the crowdfunding campaign that open sourced Blender (the first one on the internet!). I founded BlenderNation in 2006 and have been editing it every single day since then ;-) I also run the Blender Artists forum and I'm Head of Community at Sketchfab.


  1. Charlie Ringström on

    What are the GPU bugs like? Because I have experienced strange glitches when rendering on my Hackintosh GPU, which is one of the reasons to why I'm going to switch over to Windows. I see some graphics related issues, like missplaced logo textures in the dock, and worst of all after rendering for a while, it says "CUDA memory error", even though I'm just trying to render out the default cube.

      • Charlie Ringström on

        I value the "premium" feel of the OS. I love smooth animations in the interface, and it's a joy to use Mac OSX, I think. Windows 10 is looking great, but I'm not a huge fan of Windows 8. I have found that Linux looks... old. (guess I'll get a couple of billion hate replays after this comment, but whatever...)

        • TARDISMaker on

          "guess I'll get a couple of billion hate replays after this comment, but whatever..." :)

          I'd say some distro's and desktop enviroments look old, but take a quick look at GNOME 3, Unity (maybe not as much), and Cinnamon. People can even make really nice looking XFCE desktops. I guess it's just a matter of preference though. I personally think that Linux has the only nice looking desktops. I hate the look of windows, and from what I've seen of OS X, it's just not for me.

    • Sorry, but how is this why Linux is so important? As they noted, Linux doesn't have to worry about this particular issue, but nether does Windows. If anything, as a long-time critic (but dependent) of Windows, I'd say that Microsoft has been--do I dare say--IMPROVING their products as of late.

        • Competition? There's no competition. Linux doesn't give Microsoft "competition" per se, simply because Linux is (typically) not a commercial product. Linux doesn't really cut into Microsoft's market. In fact, being open-source pretty much ensures that competition is virtually impossible. The worst Linux can do is make Microsoft realize when a good idea is present.

          • I don't agree. There's a scarcity in the number of systems that require an operating system, and OS-es 'compete' for the users's preference. Competition doesn't apply only to commercial products, does it?

          • What I mean here is that Microsoft generally doesn't draw its business strategies in response to what Linux does. They're not concerned about the smaller percentage who decides to go with Linux, because they know the majority of homes, schools, and businesses will always choose Windows.

            Linux has seen some major growth in recent years, but it's still not close to robbing the predominant user preference from Windows--especially with Windows actually making some smarter design choices, for once.

            I wouldn't say that competition applies merely to commercial products, because even free software can "compete" in a sense (GIMP vs. Krita, for instance). But I would say that, in terms of comparing a FOSS to a commercial off-the-shelf (COTS) product, the comparison falls short, because you're comparing two different kinds of products with two completely different aims.

            Microsoft aims for maximal streamlined productivity. Linux aims for maximal freedom over the software. Microsoft addresses its user base's needs by hosting a rich variety of software options. Linux addresses its user base's needs by allowing anyone to contribute to its development, and hopefully, through community effort, your needs are met. Microsoft's about convenience. Linux is about control.

            If we're going to make a comparison to Windows, Linux wouldn't make for the best comparison. The nearest comparison of OS of similar commercial aims and similar design goals is OS X.

  2. Working on the MacPro dustbin is not as smooth as it could be. Adobe products are slow as hell and i can't do any hardware rendering. Lucky there's a decent processor inside that can do the heavy lifting. I

    t's a shame and a waste of money to buy a Mac for graphic work. Especially 3D. the only good thing is a clean and unified OS but it is in no way faster than Windows 7.

    I really hope this will wake up the folks @ apple and give the mac users better graphics support. They really leave the graphics profs struggeling.

    • I'm not much Microsoft fan, and I dream the day I'm going to use all my software on Linux...
      But I can not lie, my experience at Windowns 8.1 x64 is very good and everything works great.
      I still think in Cost X Benefit, the best options remain Windows 8.1 and Linux.

    • DarkCrescent on

      It's a shame; that computer was so well set up to be a beast. No other machine could have dual GPU's and run that cool. It's just Apple's drivers. Plus, if they were only going to put one CPU in there they should have gone with an i7 instead of a Xeon, those only make sense with more than one. Oh well. Maybe they'll fix that in whatever comes out next.

    • They're not so much a rip-off as they're just targeting to easy appeal among the trendy casual consumers without addressing some long-standing issues for core power users.

  3. That's kinda silly what Apple does considering that they advertised the MacPro and the ATI cards specifically with openCL. Oh man I understand that iphones and such are more lucrative but please dont trash the desktop users.

  4. It's a shame, I like Apple and OSX and it is just my preference. But I was very disappointed by the fact that it was easier for blender to support CUDA and Nvidia than OpenCL on AMD graphics cards when Apple are mainly using AMD in their current 5K iMacs and MacPros.

    When they showed off the new Mac Pro, they did a demo with Pixar characters being render in real time in a cycles-like renderer. They also showed off Mari and texturing etc, so I was hopeful that there would be some good progress with Mac and 3D going forward - but there still isn't. :( I think Apple should donate a few million to blender to help the process along lol.

    On the subject - does anyone know if the kernels AMD supplied for OpenCL are any good? Will it help get OpenCL/Cycles development on track?

  5. Charlie Ringström on

    Bart, I'm having issues with the commenting system here. I can see by mail that someone has replied to my comment, but I can't see it here on the website. Any clues?

  6. That's precisely what kind of issues you run into when you stop focusing on the needs of the artists and put too much priority on being trendy with casual users.

    Not that Macs have been the best in regard to 3D artists much to begin with. Improved attention nowadays with Maya and ZBrush for Mac, but still, just so lacking elsewhere.

    It's hard for Mac users to find a CrazyBump/Knald equivalent, for instance. Substance Designer and nDo2 are close, but not quite as convenient.

    But even when folks like LuxRender are trying to provide solution for Mac, Apple ain't making it easy. I don't think they should abandon their business model as a company (it's clearly working for them and their consumer base), but they should loosen up a bit about the driver management and stuff.

    • Fact is as much as I hate it Apple as a company is more successful than Google or Samsung. Hate it or love it but thats the reality. Both companies MS included as the third would love to have the Apple profit margin and growth.

      Thing with Apple is they go where the money is while most others don't or cannot do that.

      Sadly that also means when pro equipment brings not in much revenue they will walk away from it. Apple since a long time is not called Apple computers anymore!

      And for that I hate Apple because as much as I don't care for the hardware which however works well for what it is intended for OS X still beats linux or windows for the work I do that stretches from CAD to graphic design and 3D.

      • Apple's MOBILE market and Apple's COMPUTER market are two different things. Apple has the greatest success in the mobile industry, but for artists, we need powerful desktop machines.

        Apple's seems to have taken the approach of "casualizing" their desktop market, just to make it more compatible and trendy for their mobile users, who are generally casual users.

        Really, Apple should just divide into two sectors: Casual-user mobile market and a core-user desktop market. They need to bring some attention back to the core user of their desktops, since there are many artists out there who use Macs.

        • yep fully agree for us their strategy sucks - for being a successful company it works for them thats the odd and crazy thing about it.

    • That's not exactly a very mature comment, is it? Let's not go into a OS bashing discussion here and focus on the topic at hand.

    • Looks like you don't have much work experience with OS X - sure because it is a kiddie platform the app selection for graphic design and web exploded while for win it rather stalled.

  7. This is such an important issue. Last year I waited on a list for THREE MONTHS to get an $8000 new "trash can" MacPro (this isn't even maxed out). I found using my new machine to render previous Blender scenes a soul crushing experience. So much so, that now I build all my models in Blender and render them in Cinema 4D. Its impossible to do animations in Blender on my Mac. Its just a shame too. Because my workflow would be so much simpler if I could render everything with GPU support.

    • that is so true - it makes no sense. that MacPro was not cheap to make. Why do it when not focusing really on GPU computation and push openCL ...

  8. In order to provide a little more balanced perspective here - in my personal experience, OpenCL compute support in Houdini 14 is rock solid on Mac OS X, as it likewise is in Final Cut Pro X, Motion, and DaVinci Resolve. I find it interesting that the only developers struggling with OpenCL on Mac OS X are those working on open source 3D rendering engines.

    On a tangentially related note - the ongoing lack of OpenCL support for Cycles is generally blamed on AMD's compilers. But the recent patches provided by AMD developers to help rectify this seem to suggest that the problems have always lay more with how Brecht Lommel chose to architect the enormous Cycles kernel in the first place, rather than some kind of inherent flaw on the AMD software side of the equation. Presumably Brecht's experience working on a closed-source CUDA-based commercial rendering engine heavily informed many of the design decisions that originally went into Cycles.

    As a long term Mac user who has only ever used Blender on Mac OS X, I'm very grateful to Jens Verwiebe for all his work maintaining the Mac builds over the years. I hope he derives a great deal of joy and satisfaction with whichever platform he chooses to move to now.

    That said, I do find it somewhat bizarre to read that Jens has quit maintaining the Mac OS X builds due to "Apple's bad GPU support", and even more so that Ton chimed in with the "Apple ignores their creative users" line.


    Frankly, complaints about other companies 'bad' GPU support sound pretty ridiculous from the developers of a 3D CCS who are still trying to decide when to move 'up' to OpenGL 2.1 ... in 2015 ... 9 years after it was released! :-o

    The Mac platform has of course been derided in 3D circles over the years for lagging behind both Windows and Linux in terms of available OpenGL versions. And it's true - the current Mac OS 'only' provides built-in support for OpenGL 4.1 Core Profile, and falls back to OpenGL 2.1 (OpenGL 4.5 is current).

    Yet Blender still doesn't actually 'fall forward' to OpenGL 2.1?

    If you're wondering why that matters, try tumbling, panning and zooming around a 2 million quad poly mesh in Blender on a Mac, then import the same mesh into any other current 3D CCS - Houdini 14, Maya 2016, Cinema 4D, Modo etc. (free trials and/or learning editions are available for all of these).

    Blender will all but lock up, assuming it doesn't crash outright; the viewport performance of every other app mentioned above will basically crush it. That's currently my experience anyway (using a GeForce GTX 980).

    For me, all this begs a couple of questions:

    1. If Apple's OpenCL GPU drivers are as "broken" as Paolo Ciccone claims, why are other developers like Side Effects Software and BlackMagic Design (and Apple themselves) able to utilise these exact same drivers successfully for GPU compute tasks under Mac OS X?

    Are they more capable than the LuxRender devs, or simply more committed?

    2. When is the Blender Institute going to get it's own house in order in terms of GPU support and performance, and actually provide support for a version of OpenGL from say, anytime in the last decade?

    Maybe an online petition could get some attention from the Blender Institute?

    • zomby_32768 on

      "Maybe an online petition could get some attention from the Blender Institute?"

      I see here one difference. Blender is free, and users not forced to pay any many for Blender, so if it don't work they can just delete it. But people who buy Mac OS X paid the money, and when they found, that something is broken and not fixed for years, they write online petition.

      • I'm really not sure what you mean - Mac OS X is also free to Mac users - it has been for a number of years now. Likewise how is anyone forced to buy a Mac?

        Are you suggesting that Blender users can't complain about Blender because it didn't cost them any money?

        • zomby_32768 on

          Ok i am not Apple expert but i always thought that only way to get OS X is to buy Apple computer. And i think that OS cost is included in computer cost.
          I don't want to say that somebody forced to buy Mac but if somebody trusted Apple and pays to them hard earned money for computer and then finds that it have bug's than I think costumers have right to ask for repair or refund.
          In my point of view free programs is like a gifts and it is impolite, to complaint about gift :)

          • I think you are confusing criticism with complaints. Criticism can improve products. If people would never criticize (or even complain) products can not improve. Dmanvr has some solid points here, and input like that, especially from professional users who use other 3d software, are often valuable. On a side note, I believe the whole "Don't complain, it's free, just uninstall it of fix it yourself" attitude in OSS is not productive.

          • No, the cost of the OS is both effectively and actually free for the end user of an Apple Mac (since late 2013 at least). You do need an Apple ID (again, free) in order to download it from the Mac App Store, but that's it. Obviously the build of Mac OS X that ships on your new Mac at time of purchase could be regarded as being included in the computer's cost, but after that every major release of Mac OS X that your hardware can run is free. For reference, the current release (10.10.3) will run on some Macs as far back as 2007/2008.
            As Johann says, please don't mistake my criticisms for complaints. I don't feel that Blender's developers have a moral obligation to fix the things I'm critical of - complainers usually do though ;-)
            I don't believe the developers work on Blender as a gift to the world - that would be a pretty arrogant motivation, predicated on the belief that what you're doing is so good, people actually owe you gratitude for you doing it. No, they work on the software in the hope that someone will find it useful, and will enjoy creating with it. I actually believe that if you regularly use a piece of software that you're not paying money for, you actually owe it to the developers to be honest regarding what you don't enjoy about using it. How are they going to know what their users want if their users don't ever tell them?
            Make no mistake, If I didn't actually enjoy using Blender, I wouldn't be critical of it's shortcomings, I just wouldn't use it!
            Once I eventually grokked Blender's UI, modelling toolset and keyboard shortcuts, I actually started to find poly modelling in other apps stressful.

    • I think you hit the nail on the head. Regarding other comments also think that positive criticism like yours is highly beneficent "even" if the software is free. We want it to be better than commercial alternatives some day right?
      As a long-term osx and houdini/blender user, I must also agree that the viewport performance in blender could be improved a lot. I just followed your advice and spun a 3 million tri mesh in houdini and blender - while it did in no way lock up (macbook pro 2014) , blender is much much slower, while houdini is doing that in near real time. That being said, I read that the viewport is currently being modernized, and that will possibly bring some improvements hopefully.

      Regarding the question why guys like BlackMagic of SideFX use openCL efficiently, I would guess they probably use it in a much lower extent than a renderer would. I think houdini uses it for physics/particle effects and I guess BlackMagic uses it for some kind of specialized filters or such. I think it might be an easier job to optimize and troubleshoot their software in such scenarios.

      What I totally understand is the fact that developers (and users maybe alike) are frustrated that apple ships the graphic card drivers at the intervals they decide. I know this is due to Apple wanting to provide a complete and stable environment, but giving the user the opportunity to get a recent driver for their graphics card would also be nice.

    • --"1. If Apple's OpenCL GPU drivers are as "broken" as Paolo Ciccone claims, why are other developers like Side Effects Software and BlackMagic Design (and Apple themselves) able to utilise these exact same drivers successfully for GPU compute tasks under Mac OS X?
      Are they more capable than the LuxRender devs, or simply more committed?"

      Could it be because Side FX and BMD have the resources to devote full time devs to getting it to work and probably have commercial support contracts with Apple giving them direct access to the core OpenCL team? How many devs does Autodesk have for instance? Its got to be three figures; I'd bet that their Mac OS X team alone is bigger than the full time paid staff of Blender and Luxrender combined. And yet there are bugs in the Mac OS X version of Maya which have gone unfixed for years. Considering they aren't making a living out of developing Lux, I'd say Paolo and everyone else who contributes wins the 'commitment' prize hands down.

      --"2. When is the Blender Institute going to get it's own house in order in terms of GPU support and performance, and actually provide support for a version of OpenGL from say, anytime in the last decade?
      Maybe an online petition could get some attention from the Blender Institute?"

      The main issue is again resourcing, but even beyond this, there are other things to consider. The BI has to some extent made a conscious decision to stick with 'outdated' OpenGL because Blender is for everyone, anywhere who may want to get into 3D. 99% of the world can't afford a multicore, dual GPU Mac cylinder -- its like the Ferrari of the desktop computer word. And its not just in smaller economies; I've worked in schools in affluent parts of the word which are using PCs more than 9 years old running even older OSs and with software OpenGL implementations. Blender *does* use more modern versions of OpenGL in parts of its code it just doesn't target them as a base line. Updating OpenGL touches so much of the Blender code base that it has taken literally years of hard work by just one or two people to rewrite things to make an update possible. This work is largely unnoticed because it involves major structural changes that are not visible to users. This development is happening as fast as it can given the limited resources. If you really want to encourage BI to adopt a higher OpenGL then contribute to their dev fund rather than bashing them with a petition. I'm sure Ton and the others are more than aware of the need to evolve and update their great software.

      • I hear what you're saying in the OpenCL front, but I'm inclined to think the truth of the matter is closer to what Johann said.

        You speak truth with regard to the BI targeting as many users as possible by keeping the system requirements for Blender so ghetto.

        I also believe that well over 99% of Apple's customers (and Microsoft's for that matter) have never heard of Blender or LuxRender, nor know what OpenCL is, and will never in any way be impacted by the various issues that Paolo Ciccone, Jens Verwiebe and Ton Roosendaal have with Mac OS X.

        And for that reason, I really don't understand what the point of writing to Tim Cook is, nor the point of creating an online petition. The number of Apple customers potentially affected by these issues is so small, it might as well be zero.

        With that in mind, why would Apple as a corporation, and Tim Cook as it's CEO, care about this?

        I mean, Paolo's letter might as well read: "Hi Tim, there's this free 3D package called Blender that very, very few of your customers use, or have even heard of. Well, I work with a group of developers on a free rendering engine that even fewer of your customers use, or have heard of. So anyway, I was wondering if you could direct some engineering resources to make our stuff work with your stuff - we're pretty sure the problem lies at your end. Thanks!"

        BTW - I wasn't seriously suggesting an online petition to the Blender Institute - that was supposed to be a facetious response to Johny's suggestion above ;-)

        The Blender Institute actually do have the resources to modernise the OpenGL APIs used by Blender currently - they've simply chosen to prioritise other features and development targets right now. That's totally their prerogative, obviously.

    • My apologies if I misunderstand you ALANTI, but by your logic, an early morning walk in the local park isn't free, because citizens paid taxes and rates to the local government to cover the costs of establishing the park, and the ongoing wages of the people who maintain the park.
      I suspect you're trying to make a point, I'm just not sure what it is...

  9. How about giving some attention to the AMD issues? I was a mac fan - have for many years - and I invested into a fully loaded Mac Pro, anticipating that the dual AMD D700 cards would give my 3D rendering applications that leverage OpenCL an enormous performance increase. However, I quickly discovered that would not be the case. Bottom line, my rendering tasks were basically only 50% faster than my 2012 MacBook Pro. What a waste! I saw the trouble that developers were having with getting OpenCL to work and the complete lack of interest or response from Tim Cook or anyone at Apple and so made the only decision I could - I sold my brand new Mac Pro for a loss and built a PC with a Titan X card that functions flawlessly with all of my applications. My MacBook Pro I'm about to sell to buy an Alienware, with an NVIDIA GPU, because the new MBP's are AMD. Congrats Apple, you've killed my loyalty.

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