marshall_du wrote:
So which means both MacBook Air &Pro with M4 chip can suppport 10bit of color depth and 6k@60hz at the same time?
The Apple Pro Display XDR is a 32" 6K display that supports "P3 wide color gamut [and] 10-bit depth for 1.073 billion colors". That is probably the display that Apple has in mind – and I would guess that both M4 notebooks have the ability to drive one at 6K resolution, at 60 Hz, with 10-bit-per-channel color depth.
Over Thunderbolt. Thunderbolt provides a wide "data highway", and I believe that where the Apple 5K and 6K displays are concerned, a Mac would make two DisplayPort connections over one physical Thunderbolt cable. Each connection would carry data to refresh one half of the 5K or 6K display.
A USB-C (DisplayPort) display or adapter would be limited to 4K resolution. But I believe that USB-C (DP) can support 4K @ 60 Hz @ 10-bit-per-channel color depth. That's what the Dell 4K monitor connected to my Mac Studio claims that it is seeing.
If HDMI is involved, there may be some limitations.
- HDMI v1.4 only supports driving 4K monitors at 30 Hz. Someone started a thread recently after they couldn't get a 4K monitor to run at 60 Hz on a new Mac. Turns out that the monitor had a HDMI v1. 4 port, and that if you wanted 4K @ 60 Hz, you had to hook it up using its DisplayPort input.
- HDMI v2.0 does not support using 4K, 60 Hz, 10-bit-per-channel color, and RGB 4:4:4 encoding at the same time. Compromising on 4:4:4 encoding forces adjacent pixels to have the same color, which reduces the true resolution. So the usual tradeoff is that you can have 60 Hz OR 10-bit color, but NOT both.
- HDMI v2.1 has several times as much bandwidth as HDMI v2.0 and should not suffer these issues. But many Mac HDMI ports, monitor HDMI ports, and uSB-C to HDMI adapters do not support HDMI v2.1.