Ok - just received and tested stuff for an hour with the CAC-1085 DP1.4 to HDMI2.1 adapter. At this point I CANNOT recommend this product. It's flawed running on my 2080TI and CX48. This is what i send to Club3d Support:
Just switched back to HDMI - Text is better readable... there is something wrong with the full RGB / HDR that causes text to be fuzzy.
- Everytime I change resolution or HDR on/off or change the color profile (bits, chroma or RGC) – the adapter looses signal. Only way to recover is pull the USB Power and put it back in;
- Even when moving from in game back to windows (disabling HDR) e.g. in RDR2 – it looses signal;
- When login into windows (switching from lock screen to desktop) it looses signal;
- HDR increases the brightness of the entire panel;
- I’m not able to run 4:4:4. Only 4:2:2 or RGB;
- GSync is NOT supported;
- Custom Resolution (36840x1600) is NOT supported. Black screen like before;
- Custom Resolution (3440x1440) at 120 hz 1:1 is supported but only at 8-bit - and NO G-Sync.
That's unfortunate. For the custom resolution thing, does using GPU vs Display scaling in NVCP change anything?
The no G-Sync was a known issue so I don't hold that against them at this point.
But the rest is just not right. Are you also using a "HDMI 2.1" cable aka HDMI cable supposed to work with up to 8K 60 Hz or 4K 120 Hz? Does turning on or off the HDMI Ultra HD Deep Color make any difference in stability?
What do you mean by HDR increases the brightness of the entire panel? Does it cause black levels to shift as well? Maybe it drops to "limited" rather than full color?
EDIT: How are you connecting power? USB directly to computer or USB to something like a phone charger if it doesn't come with a power adapter?
I've got plenty of experience losing picture and other anomalies on a long HDMI cable and I think something similar might be occurring here (or otherwise the adapter is just crap). The things I have seen just from having a crap HDMI cable (where quality matters at 8+ meters) have been things like randomly missing resolutions, refresh rates, color space settings, flickering, blank screen etc.