Displayport Pixel Clock Limit

Autonomous Machines Jetson & Embedded Systems Jetson Xavier NX
1

I’m trying to use the HP Reverb G2 HMD with a Xavier NX using Displayport. A lower resolution (2880 x 1440 x 90 fps) works fine, however setting the native resolution (4320 x 2160 x 90 fps) causes the display to turn off. It seems that the max pixel clock rate for Displayport may be the issue - the limit is 540 MHz according to the Xavier NX datasheet. According to the EDID information, 2880x1440 needs 428 MHz (and works), 4320x2160 resolution needs 905 MHz (and fails).

Is this understanding correct? Is there any way to increase this limit, perhaps by configuring hardware clocks? It’s unfortunate that Displayport 1.4 HBR3 has the bandwidth to transmit much higher resolutions than the pixel clock limit would allow.

3

HBR3 on NX is not fully supported so your result is expected.

4

If this is the case, how is it possible that 8k display is experimentally supported on Xavier NX? (See Displayport support) If the pixel clock is 540 MHz, this would imply 540 Mpixel/second / (7680 x 4320) = 16.2 Hz max frame rate, which I assume is not fast enough for a usable 8k display.

If HBR3 is not supported as the NX datasheet claims, what exactly is supported?