Anyone know if the 7800XT supports FRL6?

[DmitryKo]

48 Gbps (FRL6) would allow 8-bit and 10-bit color uncompressed in 4K @ 144 Hz mode, but not 12-bit color which has to use DSC.

48 Gbps figure includes encoding overhead of 12.5% (16b/18b encoding), so effective pixel bandwidth has to be 42 Gbps or lower; for 40 Gbps transmission bandwidth, effective bandwidth is 35.55 Gbps, and for 32 Gbps (FRL4) mode, effective bandwidth is 28 Gbps.
4K @ 144 Hz mode in your monitor uses pixel clock of 1265.12 MHz - you should multiply this by 24, 30, or 36 bits per pixel (bpp), which corresponds to color depth of 8, 10, and 12 bits per color component (bpc).
The result is 30.36, 37.95, and 45.55 Gbps - which means 8-bit uncompressed requires 40 Gbps (FRL5) mode, 10-bit uncompressed requires 48 Gbps (FRL6) mode, and 12-bit uncompressed is out of available HDMI bandwidth.


That said, I don't think the Adrenalin driver currently offers any user controls to enable or disable DSC, this will be decided automatically between the display driver and monitor firmware.

 

[noatmo]

48 Gbps (FRL6) would allow 8-bit and 10-bit color uncompressed in 4K @ 144 Hz mode, but not 12-bit color.

48 Gbps figure includes encoding overhead of 12.5%, so effective pixel bandwidth has to be 42 Gbps or lower; for 40 Gbps transmission bandwidth, effective bandwidth is 35.55 Gbps, and for 32 Gbps mode, effective bandwidth is 28 Gbps.
4K @ 144 Hz mode uses pixel clock of 1265.12 MHz - you should multiply this by 24, 30, or 36 bits per pixel (bpp) - which corresponds to color depth of 8, 10, and 12 bits per color component (bpc).
The result is 30.36, 37.95, and 45.55 Gbps - which means 8-bit and 10-bit uncompressed require 40 Gbps (FRL5) mode, and 10-bit uncompressed requires 48 Gbps (FRL6) mode.


That said, I don't think the Adrenalin driver currently offers any user controls to enable or disable DSC, this will be decided automatically between the display driver and monitor firmware.

Thanks, man. I went ahead and ordered a 7800XT pure.. it was a bit of impulse decision, but hey if it doesn't work, lesson learned. I'm going to sell my 6800XT, so that softens the blow considerably.

I'll let you guys know if it fixes the bit depth issue and the waking from standby issue.

 

[noatmo]

I got the new GPU installed and it works like a dream. Defaulted to 10-bit at 144Hz, no more stand-by issues, the system is overall more responsive and I can actually enter the BIOS. I forgot to mention that, but I couldn't get into my computer's BIOS without unplugging the monitor and plugging it back in at just the right time. Now it just displays the post screen, I hit delete and it goes right in.

The card also has 90% less coil whine, way quieter fans and a healthy 10% performance increase in a couple of games that I play. Especially Star Citizen(I know..). I figured I was wasting $100, but ended up actually making love my PC.

Thanks for all the suggestions and info, guys.

 

[DmitryKo]

Thanks for the follow-up, it's good to hear your issues have been resolved with the updated display controller in a new GPU.

Are you able to use 12-bit 144 Hz mode, which would require DSC compression to fit into HDMI 2.1 bandwidth?

 

[noatmo]

Thanks for the follow-up, it's good to hear your issues have been resolved with the updated display controller in a new GPU.

Are you able to use 12-bit 144 Hz mode, which would require DSC compression to fit into HDMI 2.1 bandwidth?

Oddly enough, no. That's really odd. I only have 8 and 10-bit now. I wonder if this monitor does just have some really severe firmware issues with DSC.

Also, I know all the marketing material from VESA insists that DSC is, "visually indistinguishable" from uncompressed output, but this monitor looks far better without it. It might be placebo or maybe it just wasn't working correctly on this panel, but to my eyes I feel like I could easily tell the difference in an A to B comparison. Even static images look far more detailed now.

 

[DmitryKo]

Is there any visual indication on your monitor's screen when it uses DSC compression? Without some physical light or OSD menu item, or a lab tester that can analyze HDMI video stream, it would be hard to tell the visual difference between DSC compressed and uncompressed image.

What you described looks like some form image upscaling, which would render the content at a lower resolution then upscale it to 4K before sending the output to the display...