HDMI 10bit (Not 4k) RGB outputting 8bpc(banding)

[pinktank]

Hello all,
I have a couple displays (NEC PA243W and EIZO CS2420) that get a 8bit signal (you can see stepped gradients) if I connect them via HDMI rather than DP. Sytem report shows 10 bit still but they are definitely not operating in 10. Was wondering if anybody had any idea. I know that with 4K I would have to adjust 4:2:2 for bandwidth but this is plain old 1080p.

Do I need a framebuffer patch on the rx560?

CS2420:
  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)
  UI Looks like:    1920 x 1200
  Framebuffer Depth:    30-Bit Color (ARGB2101010)
  Main Display:    Yes
  Mirror:    Off
  Online:    Yes
  Rotation:    Supported
  Automatically Adjust Brightness:    No
  Connection Type:    DisplayPort
PA243W:
  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)
  UI Looks like:    1920 x 1200 @ 60 Hz
  Framebuffer Depth:    30-Bit Color (ARGB2101010)
  Display Serial Number:    xxxxxxxxx
  Mirror:    Off
  Online:    Yes
  Rotation:    Supported
  Automatically Adjust Brightness:    No

 

[AppleByte]

Those 2 monitors are 1080p, what do you expect?

 

[pinktank]

Those 2 monitors are 1080p, what do you expect?

I don't know why you are commenting but the question is about getting 10bit output working properly, not about resolution.

 

[AppleByte]

You're not gonna get a true 10bit color output on a consumer video cards from what i heard.

 

[pinktank]

You're not gonna get a true 10bit color output on a consumer video cards from what i heard.

Also not true, clearly stated that I am running 10bit on displayport. Besides, you can get 10bit from consumer cards. Why don't we let people who might have an actual idea chime in, no point in guessing in circles.

 

[pinktank]

Anybody?

 

[pinktank]

Still no solution