WhisperingWind It’s unlikely that disabling one GPU core would make such a big difference, since physically it’s the same M1 chip. But that’s just my assumption, based on the fact that I have an M1 MacBook Pro with 8 GPU cores and I’ve been using it with an external monitor for several years without any major issues.
Since your M1 has 8 GPU cores that means you have the 13” MacBook Pro Touchbar model. They’re the only M1 MAcBook Pros that shipped with 8 GPU cores (the 14” was 14 cores).
So we can cross off the 7 vs 8 core debate on the M1 chip.
It seems to me that the only other deciding factor is that the M1 Air, like the 13” Pro models, have the older Retina screens that have a millions of colors 8-bit capability which Apple further expands on the internal display with TCON FRC. The Mini has no TCON so it’s just outputting the raw signal.
I don’t know why, but this must mean that somewhere in the display pipeline there is a decision being made to match the internal display signal to the signal being sent to the external monitor.
In theory this makes sense. It would take too much GPU resources to process one signal differently than the other. I don’t get it since scaling should demand additional resources (perhaps this is another issue?) but if Apple wants to ensure some degree of consistency, it would make some sense.
So, if your internal display is basically operating at 8-bit with only the TCON applying sporadic FRC, and your external display isn’t utilizing FRC, it’s conceivable in my mind the Apple DCP would just sent the 8-bit signal without any processing because when GPU dithering is disabled there’s just going to be less processing on the Retina display vs. Liquid Retina or XDR which is natively configured for billions of colors.
If true this means we’re missing a huge aspect of the way all the Macs are designed within the display pipeline. I’m curious if anyone with the 13” M2 Touchbar Pros has 0 problems or if the M1 chip in the 13” Air and Pro are the only usable ones. I know future chips are difficult regardless but I don’t know whether that’s down to everything being Liquid Retina or XDR MiniLED.
