Re:Apple announces 27-inch 5K Studio Display
by Dagonfly on Wednesday March 09, 2022 @06:23PM
(#30621305)
To shed some light:
DisplayPort 2.0 supports up to 77.37 Gbit/s of bandwidth. Wikipedia's DisplayPort article has excellent tables about bandwidths of display formats: HDR 5K@120hz (57 Gbit/s) is totally possible with DP 2.0.
One could use DisplayPort 2.0 alt-mode to carry that signal over a USB-C cable. With the main disadvantage that the USB ports on the monitor would drop to USB 2.0 speeds [1]. And alt-mode 2.0 is only available on the most recent hosts with USB4 ports.
[1] Native USB4 tunneling only supports DisplayPort 1.4a (for now). That's a huge flaw imo, cause falling back to alt-mode takes over the cable and blocks USB3/PCIe tunneling from working. In fact, that flaw is even present on this monitor:
> When connected to iPad Pro 12.9-inch (3rd and 4th generation), iPad Pro 11-inch (1st and 2nd generation), or iPad Air (5th generation), Studio Display USB-C ports deliver USB 2 data transfer speeds.
Those models don't support TB3 or USB4 on their USB-C port, so they have to use alt-mode with
either compression or without HDR.
DisplayPort 2.0 supports up to 77.37 Gbit/s of bandwidth. Wikipedia's DisplayPort article has excellent tables about bandwidths of display formats: HDR 5K@120hz (57 Gbit/s) is totally possible with DP 2.0.
One could use DisplayPort 2.0 alt-mode to carry that signal over a USB-C cable. With the main disadvantage that the USB ports on the monitor would drop to USB 2.0 speeds [1]. And alt-mode 2.0 is only available on the most recent hosts with USB4 ports.
[1] Native USB4 tunneling only supports DisplayPort 1.4a (for now). That's a huge flaw imo, cause falling back to alt-mode takes over the cable and blocks USB3/PCIe tunneling from working. In fact, that flaw is even present on this monitor:
> When connected to iPad Pro 12.9-inch (3rd and 4th generation), iPad Pro 11-inch (1st and 2nd generation), or iPad Air (5th generation), Studio Display USB-C ports deliver USB 2 data transfer speeds.
Those models don't support TB3 or USB4 on their USB-C port, so they have to use alt-mode with either compression or without HDR.