CAC-1586 no 4k@120hz Amd Ryzen 5900 HX Lenovo Laptop

Updated on 27-08-2021 in USB Type C
9 on 12-08-2021

Hello Dear Club-3D Support,

I ordered a CAC-1586 usb-c to hdmi 2.1 adapter + a CAC 1372 hdmi 2.1 cable for my
lenovo slim 7 pro with a amd ryzen 5900HX Mobile CPU. The Onboard Vega GPU has display port 1.4 support and display stream compression over usb-c. It is connected to an LG C9 TV

The Problem is that it does only allow me to select 4k@60 hz and NOT 4k@120hz


Do you have an updated Firmware that could fix that?

A competitors product by cable matters with an early built in firmware allows me to select 4k@120hz

but the cable matters adapter does not have sound in this early firmware version. Later firmware versions have sound but only 4k@60hz.

Here a screenshot of the competitors product where 4k@120hz 10bit works

Here are some driver infos
The laptop uses a specific lenovo driver for amd.
Driver Info.png

GPU – AMD Radeon(TM) Graphics – Primär/Integriert
VRAM – 2048 MB – DDR4 1600 MHz
Graphics Card Manufacturer – Powered by AMD
Graphics Chipset – AMD Radeon(TM) Graphics
Device ID – 1638
Vendor ID – 1002
SubSystem ID – 3805
SubSystem Vendor ID – 17AA
Revision ID – C4
Bus Type – PCI
Current Bus Settings – PCI
BIOS Version –
BIOS Part Number – 113-CEZANNE-017
BIOS Date – 2020/11/13 02:11
Usable Memory Size – 2048 MB
Memory Type – DDR4
Memory Clock – 1600 MHz
Core Clock – 2100 MHz
Total Memory Bandwidth – 51 GByte/s
Memory Bit Rate – 3.20 Gbps
2D Driver File Path – /REGISTRY/MACHINE/SYSTEM/CurrentControlSet/Control/Class/{4d36e968-e325-11ce-bfc1-08002be10318}/0000
OpenGL® API Version – 4.6
OpenCL™ API Version – 2.0

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0 on 19-08-2021

Are you 100% sure the cable you received is the CAC-1372? It is the only flaw I could point out.

Your system should be able to connect a 4K120Hz screen without a problem.

Is it the only screen attached to the notebook? Is there anything connected to the other USB-C port?

  • Liked by
3 on 26-08-2021

sorry for late answer was on vacation,

yes, even made a pic on the cable of the device.

on 26-08-2021

Yes apart from a mouse/keyboard over a kvm switch an a different usb-a port it is. no other displays, only the internal laptop display

on 27-08-2021

Assuming you have tried without the KVM. Tried all USB-C ports? Apperantly there are 3 USB-C ports. 1 Gen 1 and 2 Gen 2s?

Tried to play with the colours? RGB / 444 / 10 bit 12 bit?

Did you try scroll down in the selection menu and go from Native to the PC part? (Resolution selection menu)

Could you link your exact laptop? Preferably from Lenovo.

Just trowing in some testing you could do.


FYI your first post had a couple of images that do not work. The last one of the CAC-1372 does work.

on 27-08-2021

Hello thanks for the reply,

yes tried without kvm, also different chrma subsampling settings.

The Laptop is a Lenovo Slim 7 pro with a ryzen 5900HX. Model 14ACH

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  • Liked by
1 on 27-08-2021

Here is the missing picture from above, the driver info

and here the screen from the competitor were it works but no sound

on 27-08-2021

Could you post your Display settings as well? Including the Display Specs shown by AMD.

Settings -> Display

Also AMD just (25th of Aug) released new Patch, are your drivers up to date?

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1 on 27-08-2021

sadly I cannot update the driver, I actually tried to install the latest amd drivers but that resulted external displays not working. Then I patched back to the lenovo driver.

As you can see in the screenshot before lenovo has custom drivers for the laptop (ending lenovo) . After reinstalling the lenovo driver, the amd adrenaline center was not installed anymore.. But external displays worked again.

so for drivers I need to wait for lenovo to make them available.

on 27-08-2021

hmm your “Current Link Settings” says 5.4 Gbps x 4.. That should be different. With 21 Gbps you can’t get 4K120Hz. It should be afaik 8.1Gbps x 4. Don’t pin me on it!

I’m not sure, I’l get back to you when I find something out.



Can you disable your Laptop screen? See if that allows the LG TV to be 4k120hz

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