Does a dead display use processing power?

[davemcollins]

Hello All,

I've spent weeks scouring the internet but I can't find the answer to this question: Does the dead display of an iMac or MacBook use any CPU/GPU power?

For example, I have a Mid 2012 13" MacBook Pro with a dead display that I've been using as a desktop (with an external display). I've been wondering if any processing power is still allocated to the built-in display...? If there is, how would I disable it so no horsepower is wasted on it?

Another example... I have been thinking about bringing new life to my MDD G4. I'm still in love with the design but obviously the hardware is a little outdated lol. First I thought about building a Hackintosh, but I really don't have any interest in those headaches. I'm a lifelong Apple user because their products just work! Sooooo... I've been looking into putting an iMac logic board (2012-2019 with dedicated GPU) into the MDD case. I can't find an easy way to connect an HDMI display to the LVDS connector (any ideas on that would be appreciated 😁) so using the Thunderbolt port appears to be the best option. Again, it got me wondering if the (now non-existent) built-in display would have any CPU/GPU allocated to it...?

Any assistance would be very much appreciated!

 

[USB3foriMac]

The GPU needs to "prepare" the image, independent of whether a display is actually connected or not.
Also, a dead display may still consume same or even higher power (current*voltage), depending on the type of fault.
For CPU/GPU usage, you can check using benchmark programs.
For power consumption, use a power meter. In old computers, it's the backlight that uses a lot of power. If that's defect or off, the power should be less than normal.

To connect HDMI, search for the display type. There are LVDS driver PCBs that can turn your internal display into an HDMI screen. Cost around $20.

 

[davemcollins]

Thank you for the reply! That’s what I figured - There’d still be overhead on the GPU because it doesn’t know the display isn’t actually there.

For that reason I did start looking into LVDS to HDMI and found the boards you mentioned. However, I couldn’t figure out if any of them would actually work. The closest I got was a thread that indicated they did not work. Do you know how I could narrow it down?

Thanks again!

 

[USB3foriMac]

However, I couldn’t figure out if any of them would actually work

You need the one for your screen model, and it will work. Maybe you can provide the source saying that it doesn't? Then we can check why someone claims so.