Enabling OpenCL on 10.7.5/mbp2012 drivers and ML GM

10.7.5/mbp2012 drivers run opencl on Fermi just fine out of box, no more need to enable it binpatching, but..

If you have a card with more than 2 gb of video memory, opencl suddenly gets disabled, wtf?

Here is why: (warning, assembler skills needed for the pic)

basicaly, if your video ram amount > 2GB by at least 1 byte, then you are screwed.

Funny Apple, they decided to control it themselves instead of putting check in the nvidia driver.

But, we can just disable the check and enjoy.

The file you wanna patch is /System/Library/Frameworks/OpenCL.framework/Versions/A/OpenCL

Just do these two simple patches you can do with any hex editor and you are good to go:

1) for 32-bit part:
find 3d 01 00 00 80 73 e7
replace with 3d 01 00 00 80 90 90

yes, its just last two bytes to disable the check
2) for 64-bit part, for lion
find ff 50 68 48 39 d8 73 e5
replace with ff 50 68 48 39 d8 90 90

for mountain lion
find ff 50 68 4c 39 e0 73 e7
replace with ff 50 68 4c 39 e0 90 90

P.S. doesnt applies to gtx670/gtx680, they have a different problem


  1. silverkid
    July 11th, 2012 | 8:47 pm

    hey netkas, i wanted to ask you something…
    would you have any idea why kepler cards like the GTX 660m or GT 640 don’t work with the latest 10.7.5 or ML GM drivers?
    is it because the support in just not there or something else…?
    Your post about patches made me think maybe we need to patch the kepler drivers for additional support?

  2. Sam
    July 11th, 2012 | 9:43 pm

    what is mean different problem?

  3. the rominator
    July 12th, 2012 | 1:43 am

    yep, works

    Good Job Mr. Netkas !!!

  4. hannibal1969
    July 12th, 2012 | 1:53 am

    Doesnt work for me. At least error with Luxmark. Nvidia Quadro 1000M…
    2012-07-12 02:53:09 – RUNTIME ERROR: PathOCL kernel compilation error

    ///thats ANOTHER error

  5. Talonette
    July 12th, 2012 | 11:41 am

    Working great, thanks Netkas !

  6. hannibal1969
    July 12th, 2012 | 3:36 pm

    Hi Netkas,

    ///thats ANOTHER error

    I know but error displayed starting LuxMark so opencl isnt working.

    You say if you have a videocard >2G you need patch as described above. You say if you have drivers 10.7.5 MBP2012, your fine,

    You don’t Say what you need to do with LM GM ? I Assume nothing because my videocard is 1GB and tried it with ML 10.8 GM

  7. Rominator
    July 12th, 2012 | 5:39 pm

    right, so you are trying to fix Problem C with solution A, it is n’t going to work.

    You have a different error, what Netkas has posted is how to fix cards that WOULD be supported but aren’t due to having MORE than 2GB of RAM.

    Since you have LESS than 2 GB, this was obviously never the solution to your problem.

  8. Kocoman
    July 12th, 2012 | 5:57 pm

    How is it possible to figure out this 2gb check?
    //few hours with gdb and ida

  9. avidist
    July 12th, 2012 | 8:36 pm

    Does anybody want to write a terminalscript for the memorycheck ?

  10. July 12th, 2012 | 9:47 pm

    So, what about HD79xx series?

  11. DaviDemon
    July 14th, 2012 | 10:53 pm

    What IF your card was already 2GB? Any issues there? I’m guessing if 2GB is part of the problem, then is that why OpenCL doesn’t work and gets green garbage in photoshop and Unigine, etc?

    //2GB isnt a problem

  12. jesse
    July 26th, 2012 | 3:15 pm

    Can anyone help me out with the hex editing part. I tried it in hexedit but upon reboot the computer won’t startup. I restored the previous version of the openCL file and restarted to get back to square one.

  13. saysosenso
    July 27th, 2012 | 5:42 am

    Be careful that you don’t delete the OpenCL file from the mentioned directory even for a second. I deleted it because I was going to copy the edited version in right away, but deleting the file from that directory caused the finder to crash unreconverably right away and my computer would no longer boot. The way I fixed the OS so it could be booted was to load the disk partition under FireWire target disk mode from another Mac that I had and copy the OpenCL file from the trash back to the proper Frameworks directory. Then the partition would boot again and I was able to drop copy & replace the file into the right directory without causing this problem. According to LuxMark OpenCL was then enabled with my EVGA GTX 570 with better performance (~200 points improvement) under ML than Lion.

  14. Alex
    July 27th, 2012 | 2:53 pm

    tryed this with my gtx 560ti 2gb by evga. luxmark still finds errors :S

  15. July 31st, 2012 | 3:40 am

    […] If your FermiĀ Nvidia Fermi Graphic Card has more then 2 GB of ram then you will still need to apply an edit. You will need Hex Edit found here and read Netkas post here. […]

  16. albert
    August 8th, 2012 | 1:10 am

    What about gtx680 ? do you have a solution ?

    Thanks in advance !

  17. Rick5
    August 14th, 2012 | 5:14 am

    Worked with my dual GTX580’s w/ 3 GB … now I can run Luxmark and that ocean thing.



  18. bill
    August 15th, 2012 | 11:50 am

    thank you! works great on my gtx470…

  19. 1ricca
    August 17th, 2012 | 4:18 am

    Nice job!!!
    Could you please update us on the gtx670, 680 “different problem? I saw you mention on a different forum that you did fix that problem as well but could never find it.

  20. August 17th, 2012 | 9:28 pm

    Edit does not work for Nvidia Quadro 6000 6GB

  21. August 19th, 2012 | 7:31 pm

    […] to get it to work. Here are the 2 links…0-680-gk104-on The second link is an addon for getting 3GB or more so look at them both and if you're fine with […]

  22. August 21st, 2012 | 6:27 pm

    […] but using luxmark I dont see my device. And whenever I try to run the netkas >2gb hex edit found here. My machine wont boot, even after repairing the permissions. So I have to boot into […]

  23. August 25th, 2012 | 3:44 am

    […] GeForce GTX 670, 680, 690 with more then 2GB video RAM. My card has 4GB on onboard video RAM. -Mrengles PS. Make note of the permissions before patching "OpenCL", you might need to […]

  24. August 27th, 2012 | 11:51 pm

    […] I've just wanted to prevent your from buying a card with 4GB memory onboard because of this issue. Of course, it can be resolved easily, but my goal is the most OBB working. Read, Read and READ […]

  25. miv
    August 28th, 2012 | 1:43 pm

    So when you say you need to patch if your card has even 1 byte over 2GB…

    …are we actually talking 1 byte over 2048MB, or 1 byte over 2000MB?

    I thought 2GB was generally meant to mean an actual amount of 2048MB, maybe this isn’t the case with video cards?

    Anyway I have an MSI GTX 660 Ti (OC) that appeared to work fine with the CL enabler from Multibeast (tonymacx86).#

    I’m planning to do a fresh system install and wondered if I should just stick with the MB patch or try your method (assuming that I may be 48MB over 2GB depending on the definition of a GB).


    /// 1-byte over 2048 mbytes

  26. September 12th, 2012 | 11:01 pm

    […] If that does not fix it, then there is one other thing you will have to do t. Heres is the link. It is very easy to do., Tweet !function(d,s,id){var […]

  27. September 19th, 2012 | 4:49 pm

    Great, finally worked. I accidentally deleted the OpenCl file and tried to replace it with the new version, but of course my whole system crashed.

    This time I replaced it and it works great with my GTX 570 2.5GB.

    Thanks netkas!

  28. September 21st, 2012 | 7:59 pm

    […] 1) LION, openCL on 2gb+ cards, this fix still works – […]

  29. holkov
    September 23rd, 2012 | 9:52 am

    hey mr netkas do you have any solution for geforce 8400GS ,please help

  30. nick levanti
    September 25th, 2012 | 1:03 am

    I’m on 10.7.5 and i’ve got the nvidia drivers installed and the gtx 570 seems to be working, but seems to be underperforming. I have been trying to do this open cl fix but every time I do it, my tower will not boot until I target disc mode in and replace the opencl file with the backup of the original i’m keeping.

    I replace the strings specified in this guide, then move the new open cl file into the folder with the other to replace it, but this causes the finder to crash and the tower to not boot.

    I also tried using target disc mode to replace the opencl file with the one with the new strings to avoid the finder crashing, but this also prevents my tower from booting.

    Anyone have any ideas?

  31. joe
    September 27th, 2012 | 6:15 pm

    Finally I found some useful help for the GTX570 2.5GB in ML. I have ML installed and running but after putting my graphics card back in I can’t boot into OSX. I am confused on what to do next. Do I take my card out, boot into ML and make these changes? Or do I need to also install some NVIDIA drivers? I couldnt find any that listed the 5xx as supported. I’m also a little confused about the hex edits and how to do them. Thanks for all the help!

  32. joe
    September 28th, 2012 | 6:27 pm

    Ok, so I installed the CUDA 5 driverby, and then made the hexedit changes. I shutdown and put my gtx570 2.5GB back in and it still won’t boot into osx. it gets to the apple screen and then goes black and the monitor goes to sleep. I am using the i7-3770k and ASUS p8z77-v deluxe. Does anyone know a fix?

  33. joe
    September 28th, 2012 | 9:37 pm

    So I found out how to update the NVIDIA driver even though it says it is updated. I can boot fine in safe mode but luxmark shows the openCL error. When I try to boot normally I get to the login screen but every login attempt just loops back to the login screen. Any ideas?

  34. October 7th, 2012 | 6:52 pm

    Hello I ran CINEBench OPENGL without the hex change and got comparable results from their recorded reference (GTX570). I have a GTX 570 from (macvidcards) that scored 25.66fps Cinebench GTX marked 25.16 my GPU: 12C/24T @2.4Ghz Nvidia GeForce GTX560 Ti OpenGl engine Cinebench: 12C/24T @2.4Ghz Nvidia GeForce GTX570 OpenGl engine I am not familiar with what the expected performance should be, but should I been scoring better than their number is my system is supposed to have openGL not working? many thanks and sorry for my lack of experience :0

  35. October 9th, 2012 | 1:44 am

    […] OpenCL patch didn't work Also Netkas site also explains what needs to be done depending on the OS Then download LuxMark to see if it worked and give us your benchmark. […]

  36. Tim
    October 11th, 2012 | 5:55 am

    Hi, im having a bit of a problem with the above open cl fix – i am obviously doing something wrong but cant seem to figure it out! this is what has been happening to me… I’m running osx10.8.2 on a 4.1 Mac Pro 2009, Installed GTX 570 AND GT 120 from macvidcards successfully – they both appear in system profiler Install Latest 10.8.2 driver and cuda driver from nvidia – and – I’m dragging a copy of the whole open cl frameworks folder to the desktop then fixing the open cl file as in the above fix for 32bit part and mountain lion part, then saving the file (with HEX EDIT ) and replacing the folder with the one in the frameworks folder. I then repair disc permissions And re start, My Mac Pro gets stuck with the grey screen and apple logo and spinning wheel- the only way to fix is to resinstall the OS – have done this 3 times now! Any help as to what i am doing wrong would be really appreciated ! Thanks in advance!

  37. SpikedBR
    October 11th, 2012 | 8:14 pm

    joe i had this problem too, u`ll need to delete the Nvidia drivers, then reboot, login, install the drivers AND the OpenCL multibeast patch again… That solved for me. The problem happens when you update the nvidia driver and forget to re-do the OpenCL patch.

  38. vik
    August 9th, 2013 | 7:50 am

    Hello Netkas.

    I am not an expert like most people here i think but my question is does this also work for a Mac pro 5.1 12 core?

    I have 10.7.5 and a gtx 570 2.5 gb macvidcards edition and could opencl before but now i just can’t seem to fix it.

    When i apply the patch do i use replace all in hex editior?

    Do i need to apply both the 32 and 64 bit fix?

    What program do i use after the patch?

    Thanks in advance

  39. Sasha
    May 14th, 2015 | 5:44 pm

    Hello Netkas

    I am running Yosemite and fcpx I installed a GTX 570 and it show up in the system profiler, how do I know if FCPX is using the GPU is there any way to test this? my Cuda Drivers are 7.0

    Any Help would be great I can’t find any information on this topic on the web

  40. christer caramon
    June 14th, 2016 | 4:09 am

    More to lion, kindly regards

  41. June 14th, 2016 | 4:12 am

    Work more for mac lion 10.7.5?

  42. Costas
    May 15th, 2017 | 2:04 pm

    Hey Netkas!
    Do you have a workaround for activating Open CL on a Quadro 4000 running on Sierra?
    Trying to get it to work with FCPX..

    Thanks dude, you rock!

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