GTX 970 Not Working Without CSM

[floodlitworld]

I'm trying to work out how to ditch having CSM enabled on my BIOS since it messes up the boot process and sends POST to my 2nd monitor (which isn't always on). 

 

At the moment, if I go into my BIOS and disable CSM, then my system will boot, but seemingly without loading the web drivers (very slow, stuttery display, same as booting without web driver when first installing a hackintosh). Furthermore, if I change my display settings in BIOS from Auto, to PEG, then my main display (Display Port) dies completely and then the 2nd display will die before the final MacOS process loads. Got Lilu and Driver fix installed already.

[nikitenich]

The same problem with my GTX 980: when I turn on 2 monitors without an CSM, the image stops coming to the displays at the moment of transition to graphic mode, and the fans on the videocard begin to spin at maximum speed.

With one monitor without CSM and with two with CSM, there is no such problem.

I didn't find a solution.

[nmano]

try this 

 

            #400            

[nikitenich]

I find the solution for Sierra!

Inject with arbitary @X,AAPL,boot-display property for your boot display (the one that works in BIOS without the CSM), where X is number of your boot display in ioreg.

It is determined by turning off the monitor and checking the ioreg changes. In my case it's 4.

In High Sierra this solution doesn't work - black screen on both monitors.

<key>Arbitrary</key>
        <array>
            <dict>
                <key>Comment</key>
                <string>Nvidia Display</string>
                <key>CustomProperties</key>
                <array>
                    <dict>
                        <key>Key</key>
                        <string>@4,AAPL,boot-display</string>
                        <key>Value</key>
                        <data>
                        </data>
                    </dict>
                </array>
                <key>PciAddr</key>
                <string>01:00.00</string>
            </dict>
        </array>