2011 27” iMac GPU Brightness Question

[HelpMePls]

I have a 2011 27” (not 21.5) iMac needing an GPU replacement that’s NOT prone to failure as the current AMD Radeon 6970m graphics video card is notorious for.

However after watching this guy on YouTube replace his AMD Radeon 6970m video card with an Nvidia GTX 765M video card ONLY to realise in the comment section he SWAPPED out that GTX 765m and put another AMD in there because of brightness issues -

My question is - currently is there ANY existing GPU I can put in the iMac where it DOESN’T stuff around with the brightness as you can see here -

I understand there’s a million and one posts in this thread.

But I don’t understand what they mean by “these cards offer right now native brightness”.

What is native brightness? Will it use an dark overlay as that guy mentioned in the comments above and make all your screenshots dark?

Thank you in advance!

 

[bmxburner]

Native brightness means exactly that - it works like before with the AMD card using the keys on your keyboard adjusting the actual brightness of the lcd screen. It is not the easiest thing to setup though, I’ve done it. You have to change the firmware on the card and run OpenCore to boot the Mac like a hackintosh.

 

[herrdude]

260 pages of fascinating discussion on the same subject: https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/

Enjoy!

 

[highvoltage12v]

Long story short. Find a k1100M/k2100M (needs to be flashed) MXM card then boot your iMac with OpenCore and brightness function will be restored.
Also like @herrdude said 260 pages of useful information on this topic.

 

[Lottosmp]

If you feel comfortable with a tiny bit of soldering, I just modified my Late 2009 iMac 27 with an ESP32 that's generating a new PWM signal. The soldering is just to extend a wire on a $7 wire harness you need to buy, everything is reversible no changes to the Mac's original components.

That writeup is a bit long but you just need to get a 6pin PCI-E extension harness, cut 1 wire and route it to the ESP32 running micropython, which can be connected to a USB port internally or externally. You need to run a little app to send commands to the ESP but it behaves like normal brightness control then.

iMac 2009 / 2010 / 2011 GPU upgrade - Fixing LED/LCD PWM brightness with an ESP32

iMac 2009â2011 GPU upgrade PWM backlight modâââregain brightness control after upgrading to an unsupported non-Apple GPU.

medium.com

 

[crizzly]

If you feel comfortable with a tiny bit of soldering, I just modified my Late 2009 iMac 27 with an ESP32 that's generating a new PWM signal. The soldering is just to extend a wire on a $7 wire harness you need to buy, everything is reversible no changes to the Mac's original components.

That writeup is a bit long but you just need to get a 6pin PCI-E extension harness, cut 1 wire and route it to the ESP32 running micropython, which can be connected to a USB port internally or externally. You need to run a little app to send commands to the ESP but it behaves like normal brightness control then.

iMac 2009 / 2010 / 2011 GPU upgrade - Fixing LED/LCD PWM brightness with an ESP32

iMac 2009â2011 GPU upgrade PWM backlight modâââregain brightness control after upgrading to an unsupported non-Apple GPU.

medium.com

Does the code work on ESP8266 also?

 

[bkook74]

It seems that True native brightness control cannot be achieved with anyMXM GPU swap. I understand from ESP32 installation, all non Apple GPU are missing voltage control. Is there any non Apple one with built in voltage control? It sounds ridiculous that Apple is the only company implemented soft key brightness control on their machine.

 

[highvoltage12v]

It seems that True native brightness control cannot be achieved with anyMXM GPU swap. I understand from ESP32 installation, all non Apple GPU are missing voltage control. Is there any non Apple one with built in voltage control? It sounds ridiculous that Apple is the only company implemented soft key brightness control on their machine.

The AMD WX series cards do have native brightness control when flashed with an EG2 ROM. Currently there is a ROM that can show bootscreen when a 2nd monitor is connected.

Nvidia cards have brightness control as well such as the GTX 780M, they need a Kext edit to keep the Brightness stepping levels correct. Have you seen the MXM thread?