?intel based macbook accessing openfirmware
hi i'm new to the forum, it's been days i'm looking for a solution.
i have a mackbook pro, intel based with integrated iris 5200 and a nvidia 750M
osx is awesome it permits to load dual gpu while windows not
i installed using bootcamp windows 8.1 and as default it loads the nvidia 750m, hiding the iris.
what i'm looking for.. is a way on how to turn off the nvidia 750 for the sake of the iris pro 5200.
the iris pro is 4 times faster then the nvidia 750m with opencl.
in windows, i would load the bios and simply disable the nvidia graphic card, but mac doesn't has bios but open firmware.
i can't access this firmware with the command cmd+opt+o+f while reebooting, it doesn't work, because as i read it is for not mac running intel chipset.
i installed refit, but i can only boot to win, mac or in the recovery partition of mac.
could some help me? or tell me if what i'm trying to do is ok?
Comments
You should be able to use OpenCL without it using the Intel GPU for graphics. You might need to install Intel's OpenCL SDK for it to show up as a compute device:
https://software.intel.com/en-us/intel-opencl
hi thanks for the answer.
the problem is that in windows, the iris is invisible for the environment, only the nvidia 750m is visible
i already installed the intel opencl sdk and the opencl runtime too.
i uninstalled the nvidia drivers also from the device manager..
but on reboot the iris is not available. the device manager show the microsoft default display drivers only.
i need to access the open firmware and disable the nvidia from there..
same happened to me in the past once i bought an acer with win 7, intel integrated graphic card and a nvidia 330m.
to can install the nvidia drivers i had to permanently disable from bios the integrated intel graphic card.. until that while trying to install the nvidia drivers the message was always the same: this computer is not supported.
thanks
Have you tried installing the Intel GPU drivers from here:
https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=24245
of course i did.. also the zipped one.. i try to install as first the legacy intel graphic drivers that bootcamp did dowload for me.. but nothing
it has simply to do with the fact that the iris pro 5200 is not recognized until the nvidia 750 is enbled in bios=open firmware
besides.. i tried already to install all the inteliris drivers version i coud find..
There's a procedure here for doing this for Linux, it might work for Windows too:
https://wiki.archlinux.org/index.php/MacBookPro11,x#Getting_the_integrated_intel_card_to_work_on_11.2C3
Apple locked down the EFI so you can't access it directly but there are custom bootloaders, check the note about Yosemite:
http://www.rodsbooks.com/refind/getting.html
http://www.rodsbooks.com/refind/yosemite.html
http://www.rodsbooks.com/refind/
thank you.. i will give it a try.. i will report back.. thanks
There's a procedure here for doing this for Linux, it might work for Windows too:
https://wiki.archlinux.org/index.php/MacBookPro11,x#Getting_the_integrated_intel_card_to_work_on_11.2C3
Apple locked down the EFI so you can't access it directly but there are custom bootloaders, check the note about Yosemite:
http://www.rodsbooks.com/refind/getting.html
http://www.rodsbooks.com/refind/yosemite.html
http://www.rodsbooks.com/refind/
He should really back up that drive prior to installing refind. That replaces your default bootloader, although you should still be able to use key overrides if necessary. It's also important to read the documentation prior to doing that. There are a few things that can cause problematic behavior, such as the use of other utilities in conjunction with refind.
He should really back up that drive prior to installing refind.
isn't the mac recovery partition safe from changes when using refind?
isn't the mac recovery partition safe from changes when using refind?
I wouldn't chance it when using something like a bootloader. As I recall it is possible to use the option key anyway, but you won't see the normal loading screen.
I wouldn't chance it when using something like a bootloader. As I recall it is possible to use the option key anyway, but you won't see the normal loading screen.
i installed and already uninstalled refit.. it was useless for me.
it is kinda same as refind, but refind has few option more like the console and the drive beside the console..