[joevt]

No, I am not sure.

A Thunderbolt 4 cable should work. But since it doesn’t, then what is there for you to do?

Basically, when trouble shooting a problem, it helps to find what works by replacing parts – drivers, computer, gpu, cable, display, etc.

Have you verified with another display that the L14 can output a signal from its USB-C ports?

The Studio Display is not Thunderbolt 4 so it might not have a Thunderbolt 4 cable. It might be a Thunderbolt 3 cable.

[joevt]

Over the air digital converter just produces an HDMI signal. It shouldn’t be any different than an HDMI signal produced by any other source such as a PC or gaming console.

If you can get it to work with a normal display then it should work with the Apple Studio Display.

However, the Apple Studio Display is not as normal as it should be. People have difficulty getting it to work with normal DisplayPort and HDMI to DisplayPort connections.

See https://insights.club-3d.com/thread/lenovo-l14-hdmi-apple-studio-display-cac-1333-2/

You should test the sources and displays and cables and adapters with other sources and displays and cables and adapters to see what works.

[joevt]

The spec says both USB-C ports support DisplayPort 1.2 so that’s what I would use to connect the display.

The USB-C cable needs to be able to support 10 Gbps data transfer.

Some USB-C cables are only for charging which means they are USB 2.0 only (480 Mb/s). I suppose if you used such a cable then you wouldn’t see any image at all – no flickering – just black – like no connection.

Have you verified with another computer that the Apple Studio Display works without flickering?

Update graphics drivers?

 

[joevt]

A CAC-1332 might be preferable because it includes a USB 2.0 connection to support the USB devices of the display (audio, camera, brightness control, USB ports, etc.). I don’t think club-3d makes the CAC-1332 anymore. In that case, there’s the CAC-1336 which can do 5K, unlike the earlier adapters, but that depends on the GPU.

I don’t know if the CAC-1332 or CAC-1336 will work better with the Apple Studio Display than your CAC-1333.

One thing I would try is replacing the Thunderbolt cable with a normal USB cable (10 Gbps).

Another thing I would try is putting a Thunderbolt 4 hub between the adapter and the display. It helps with the CAC-1336 for non-USB-C displays.

Exactly which Lenovo L14 do you have?

The Lenovo L14 only has HDMI 1.4? That might be good enough for 1440p60.

Doesn’t the Lenovo L14 have a USB-C port that supports USB-C DisplayPort Alt Mode? I would try that.

[joevt]

What GPU does the HP Elitebook have? The GPU needs to support DSC to achieve 5K60 from a non-Thunderbolt computer. Without DSC or Thunderbolt, you will need to create a lower refresh rate timing to achieve 5K. An LG UltraFine 5K can do 5K39 from DisplayPort. The Apple Studio Display might be able to do 5K47 from DisplayPort.

Did you test the USB-C port of the HP Elitebook with any other displays?

A USB-C connection would be the best option. Does the USB-C (Thunderbolt 3) cable work with a USB device (external storage) that can do more than 5 Gbps? A Thunderbolt 4 cable might be a better option since it’s guaranteed to work with non Thunderbolt devices. I suppose a passive Thunderbolt 3 cable should also work but I’m not 100% sure.

With the CAC-1336, it may help to put a Thunderbolt 4 hub between the CAC-1336 and the USB-C display, but the Studio Display is like a Thunderbolt 3 hub already so it might not be helpful in this case but if you have such a hub lying around, it won’t hurt to try it.

[joevt]

The CAC-1010 is directly connected to your GPU?

Update drivers?

If that doesn’t work, then maybe try Custom Resolution Utility (CRU).

 

[joevt]

Those instructions must be for a CAC-1010, not the CAC-1510, since the CAC-1510 uses a USB-C connection for both DisplayPort and USB power.

For the CAC-1010, the DisplayPort connector doesn’t have enough power to do the DisplayPort to Dual Link DVI conversion, so that adapter includes a USB-A connector to get the additional power.
https://www.club-3d.com/en/detail/2526/displayport_to_dual_link_dvi_d_hdcp_off_version_active_adapter_m-f_for_apple_cinema_displays/

For people that have the CAC-1010, the “all types of OS” refers to all OSes, including Mac OS X, OS X, and macOS.
https://en.wikipedia.org/wiki/MacOS

For the CAC-1510, just plug it into a USB-C port that supports USB-C Display Port Alt Mode. This includes all Thunderbolt 3 and Thunderbolt 4 ports and most USB4 ports.

The CAC-1010 and CAC-1510 and probably all other DisplayPort to Dual Link DVI adapters require 4 lanes of DisplayPort (with HBR link rate) to achieve 2560×1440 60Hz or 2560×1600 60Hz or 3840×2160 30Hz. Some USB-C docks might only support 2 lanes of DisplayPort. That’s not a problem with a direct connect to a Thunderbolt/USB4 of a host computer or a Thunderbolt dock. An MST hub can be used to convert 2 lanes of HBR2 or HBR3 to 4 lanes of HBR. Some USB-C docks include an MST hub.

[joevt]

Drivers. Of course! 🙂 Glad it’s working for you now.

I usually use Driver Genius to to keep my drivers up to date, though sometimes (rarely) it might find something you don’t want to install. For example, it was using an NVMe driver that Samsung Magician doesn’t support. But there’s a way to switch drivers in a situation like that and to hide the offending NVMe driver from Driver Genius.

[joevt]

Have you tested the adapter with any other GPU or computer? Maybe it’s an issue with Intel ARC.

Did you check the EDID of the display to determine if it supports HDCP or not? There are old 30″ Cinema HD Displays that don’t and newer ones that do. Maybe a firmware update to the HDCP-ON firmware might change things but I don’t know how that could help get 2560×1600 if 1280×800 already works.

 

[joevt]

In CRU, you can click the Edit… button next to the display name and change the display name. That will show that the custom EDID is definitely being used. Note that the custom EDID only applies to the port that the display is currently connected to. To apply the custom EDID to other ports, you can use CRU to copy the EDID from one to the other.

Is the CAC-1010-A connected directly to the Intel ARC A750? The CAC-1010-A (and every other DisplayPort to Dual Link DVI adapter) requires 4 lanes of HBR to do 2560×1600. A USB-C hub usually only has 2 lanes of DisplayPort.

Have you tried clicking Advanced Display Settings then clicking on Display adapter properties and List all Modes?

[joevt]

Here’s another PS196 based adapter:
https://www.centrecom.com.au/cruxtec-2m-displayport-14-to-hdmi-21-cable-8k60hz-4k120hz

[joevt]

The Parade PS196 is supposed to support VRR but I don’t know if any adapters exist yet that use that chip.
https://www.paradetech.com/products/ps196/

Here’s something but I don’t know if you can get it or if it supports VRR.
https://www.hoyunwholesale.com/products/cruxtec-usb-c-to-hdmi-2-1-cable-support-hdr-8k-60hz-4k-120hz

[joevt]

4K120 requires 1076 MHz (CVT-RB2) or 1098 MHz (CVT-RB) or 1188 MHz (HDM).

WQHD is 2560×1440. 2560×1440@165Hz requires between 678 or 700 MHz.

Ultra WQHD is 3440×1440. The manual shows 165Hz is 879.714 MHz which is still less than 4K120.

The highest WQHD refresh rate shown in the manual is only 120Hz (for DisplayPort). I guess the display scaler can’t scale 2560×1440 165Hz to 3440×1440? I suppose you can test that with a custom timing.

In either case, the highest refresh rate for HDMI shown in the manual is 100Hz (410 MHz). HDMI 2.0 can do 8bpc 4:4:4 up to 600MHz and 10bpc 4:4:4 up to 480MHz so maybe a custom timing can do better than 100Hz? Chroma sub sampling can increase that further (if the display supports it).

[joevt]

Notice that the pinkish pixels only appear on the dark gray areas. There’s no pinkish pixels for the text that is drawn on the black areas. Could this be a chroma subsampling issue? The pinkish pixels only appear for vertical lines which would suggest 4:2:2 instead of 4:2:0. You want 4:4:4 or RGB.

[joevt]

I think the only limit of HDMI is the bandwidth. 5K should be possible if the refresh rate is low enough. HDMI 2.0 can do pixel clock 600MHz with 8bpc RGB. 5K 39Hz should work with CVT-RB2 timing. I would test that from Thunderbolt port first, then try it from HDMI after.

I did not talk to Club-3D support about the CAC-1336. If they wanted to be helpful, they could contribute to these forum posts but they don’t.

macOS can’t see the CAC-1336 except for connected USB devices (you should see the USB hub of the USB-C display) and whatever is presented to the HDMI port. At least the EDID of the display should be readable. When it’s not working, the EDID is has device name CHD-LT2610 (visible in Windows). When it does work, the EDID should match the EDID of the display.

For Intel Macs, I can use my AllRez utility to read the EDID. I haven’t updated that part for Apple Silicon Macs. I don’t remember if AllRez can read the EDID when the display is not detected. I  believe it can read EDID from all ports of all GPUs. But if an EDID were readable, why wouldn’t it show a display connected? I’ve packed away the adapter so I can’t retest it for a couple weeks.

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