# Improving heat management after macbookpro 2011 discrete GPU fix, also a script to automate part of the fix process

> Taken from [StackExchange](https://apple.stackexchange.com/questions/267581/gpu-problem-boot-hangs-on-grey-screen/295805#295805)

> Thanks to [LangLangC](https://apple.stackexchange.com/users/251859/langlangc)


### Improved thermal and power management

#### Open Terminal.app

#### Create login hook folder for thermal and power management
```shell
sudo mkdir -p /Library/LoginHook
```

#### Create login hook file
```shell
sudo nano /Library/LoginHook/LoadX3000.sh
```

#### Add folowing contents when nano opens
```shell
#!/bin/bash
kextload  /System/Library/Extensions-off/AMDRadeonX3000.kext
pmset -a force gpuswitch 0    # undocumented/experimental
exit 0
```
> Use `ctrl + o` to save and `ctrl + x` exit

#### Make it executable
```shell
sudo chmod a+x /Library/LoginHook/LoadX3000.sh
```

#### Register login hook 
```shell
sudo defaults write com.apple.loginwindow LoginHook /Library/LoginHook/LoadX3000.sh
```

#### Reboot normally

#### Check that proper kexts exist
```shell
kextstat | grep AMD
```

#### The command above should display
```shell
... com.apple.kext.AMDLegacySupport (1.5.1) ...
... com.apple.kext.AMD6000Controller (1.5.1) ...
... com.apple.kext.AMDSupport (1.5.1) ...
... com.apple.kext.AMDLegacyFramebuffer (1.5.1) ...

And this
... com.apple.AMDRadeonX3000 (1.5.1)  ...

should also appear on the list
```

#### Reboot normally

#### Boot into single user recovery by pressing on boot
```shell
Command + r + s
```

#### Modify NVRAM
```shell
nvram boot-args="-v agc=0"
```

#### Reboot
```shell
reboot
```

### Script ot make part of the process automatic

#### Open terminal

#### Create script
```shell
sudo nano /force-iGPU-boot.sh
```

#### Add contents
```shell
#/bin/sh
sudo nvram boot-args="-v"
sudo nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00
exit 0
```

#### Make exectuable
```shell
sudo chmod a+x /force-iGPU-boot.sh
```

#### When booting into single user mode (`Cmd + r or CMD + r + s`) use
```shell
sh /force-iGPU-boot.sh
```