CAC-1085 not working with AMD 5700XT

8 replies #M143834">https://community.amd.com/t5/drivers-software/5700-xt-display-port-bandwidth-limited-to-5-4gbps-x-4-with-use/m-p/469668#M143834

I have the CAC-1085 with your 2 meter hdmi cable (CAC-1372) and the 5700xt AMD GPU. I am connecting to an LG CX OLED 48" display.

The GPU drivers are up-to-date, it supports DP 1.4 and has successfully used Displaystream Compression in the past on other monitors.

The LG display is up-to-date and in the proper mode to receive 444 in 120hz (it's in PC mode).

The adapter works and is plugged into a power supply. The HDMI cable supports 48gbps (it is Club3D's own HDMI cable).

Even with all this, I cannot get the adaptor to work properly. It seems like the Displaystream Compression chip in the adaptor is not being recognized, so the bandwidth is being limited to 4k@60hz.

Bandwidth shouldn't be limited to HDMI 2.0 rates through a DP 1.4 port on your 5700 XT or there is other software/hardware issues elsewhere with your card.

I have the same display, although using a GTX 1660. If you are getting a black screen when trying to change to 4k @ 120hz, try unplugging/replugging the adapter and even if the resolution/refresh rate shows its already selected, try selecting it again as the adapter can be finicky and tries to read the display mode before waiting for the user to confirm the change.

DP 1.4 can provide up to 4k@120hz 8-bit 4:4:4  RGB color without the need for DSC (~32gbps). So unless you use 4k@120hz 10-bit 4:4:4 RGB color, there shouldn't be any DSC involved.

CAC-1085 not working with AMD RADEON VII

I have similar setup almost.. Radeon VII and a LG CX OLED. This only shows the panel can output 60Hz. I am using a Certified Cable Zeskit 8K Ultra HD High Speed 48Gpbs HDMI -Anyone get this working with a Radeon card?? I have latest drivers from AMD, Newest Firmware for LG CX.. Supports Freesync and Gsync. High Color UHD depth turned on.  Port is certified for 120hz.   Tried multiple Display Ports on my card.. Same thing never will do above 8 bit and 60 Hz

Were you able to resolve this? I'm having the same problem with my Radeon VII and LG CX 48

Can you please upload the firmware to google drive, catbox.moe, anonfiles or some other image host and post it here? 

Many people are having this problem and the firmware isnt publicly available anywhere it would help many people including me

The firmware update on the CAC-1085 did nothing to convince my 5700 XT to output 32 Gbps, but it did resolve some flickering issues.

You're not the only one experiencing this with a 5700 XT. I'm running a 5700 XT, LG CX 48", and Zeskit 48 Gbs HDMI cable and am experiencing the same thing.

There is an ongoing thread on AMD's forums discussing this:  https://community.amd.com/t5/drivers-software/5700-xt-display-port-bandwidth-limited-to-5-4gbps-x-4-with-use/m-p/469668#M143834

Club3D's response seems to indicated that there are some variant's of the 5700 XT that aren't DisplayPort 1.4 (HBR3) compliant and are incapable of 32 Gbps (8.1 Gbps x 4). AMD support claims this is not the case, but I don't have the hardware to verify it one way or the other.

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