As other users, my Mac Book Pro 8,3 have a fail dGPU ( AMD Radeon HD 6750M ).
Start with Single User Mode. After end all procedures, write:
sudo nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00
Press Command + R to access to the Recover Mode. In Utilities Menu, open Terminal and disable SIP writing:
After the process ends, write:
And let your computer start as always.
If all works fine at this level.
Download "KEXTUTILITY" After that go to /System/Library/Extensions/
And manually move the kext: AMDRadeonX3000.kext to other folder outside Extensions.
After that open KextUtil and let operate changing permissions and caches.
Then your computer will work without the dGPU.
Add more VRAM
As you may think, working with a computar only with a integrated GPU, may produce glitches in the screen. In fact in some circumstances this happens. ( for example editing in Photos ).
To solve this, open the Terminal and do this 2 steps:
1) Before reboot/restart you have to edit this file:
/System/Library/Extensions/AppleIntelHD3000Graphics.kext/Contents/Info.plist with TextEdit for example.
Add after the last sentence these strings exacltly:
VRAMMethod 0 VRAMOverride 0 VRAMSize 2048
After that save the file and close all but DO NOT RESTART.
2) Open the Terminal Application and write this:
sudo cp AppleIntelSNBGraphicsFB AppleIntelSNBGraphicsFB.backup
sudo perl -pi -e 's|\xC7\x45\xD0\x00\x00\x00\x20| \xC7\x45\xD0\x00\x00\x00\x60|g' AppleIntelSNBGraphicsFB
sudo touch /S*/L*/Extensions
Quit Terminal and open KextUtility again.
After that Reboot.
After this procedure the shared VRAM will be 1536 Mb
I recomend download: - Macs Fan Control to be aware with the System Temperatures. - GfxCardStatus to review how works the GPU
Add RAM: As you may see, my MBP is running with 16 Gb RAM. This is very necessary because the RAM is sharing memory to the iGPU. Then when open large files my MBP works without troubles.
Change the HDD to a SSD: next step to me is change the stock HDD to one 1 Tb SSD drive. I think no more comments to this. It is faster and more safe.
Last think is change the original Bluetooth Card to the model BCM94331PCIEBT4CAX installed originally in a 2012 MacBook Pro.
After it is installed, download CAT ( CONTINUITY ACTIVATION TOOL ) And voila!! Your Mac will run as one of 2017. Except for some things:
- Cant connect external monitors
- USB 2 can't be changed.
- The display is not Retina.
I hope this will be helpful.