VESA Reveals How To Get 80Gbps From 40Gbps
We know a fair bit about the upcoming, and sensibly named, USB 4 specification as well as the new DisplayPort 2 interface but the idea that USB 4 will support DP2 connections is news. The DP2 specification will allow the use of 8K displays running at a 60Hz refresh rate with full 4:4:4 colour thanks to it having 77.37 Gbps available for the signal to make use of. You would also be able to feed a 16K display if you had the desire and equipment.
USB 4 will finally offer the same 40Gbps bi-directional bandwidth that true Thunderbolt 3 provides, keeping the well designed USB-C plug as well. This leads us to the lede, the question of how is USB 4 going to be able to provide twice it’s stated bandwidth and the answer is relatively simple. Since monitors and TVs only tend to receive signals and do not send anything back to the video source, so by remapping the pins which would generally communicate back to your device to also send, you double your bandwidth to 80Gbps.
There is more good news about DisplayPort Alt Mode 2.0 as well. Thanks to this implementation, your display will not need a USB controller to receive the signal which lowers the design complexity as well as the price. It is worth mentioning that if you require a USB-C to DisplayPort adapter in order to plug into your display, it will now need to be an active adapter unlike the current interface which can work with a passive one.
Slashdot collected a few links to different sources on this nifty trick if you would like to do some digging on your own.
Alt Mode 2.0 will support regular USB 4 cables. At the same time, monitors won't need to have USB 4 controllers, which should simplify display designs. Since it also supports the Thunderbolt 3 standard, USB 4 will become a universal connection standard for both smartphones and PCs, supporting things like "docking, gaming, AR/VR HMDs, and professional HDR displays," VESA said.