[joevt]

I see Synaptics has some chips that can output HDMI 2.1.
VMM8210, VMM8100, VMM6210, VMM6100

I see some products (not North America?) are using the VMM6100. I wonder how it compares to devices that use the Realtek chip.
 https://www.alibaba.com/product-detail/8K-Aluminum-Shell-6-tf-USB_1600237683163.html?spm=a2700.galleryofferlist.normal_offer.d_title.3d42650020u6OL

 

[joevt]

Blame ASUS (and every other PC laptop manufacturer) for not describing the GPU/display connection capabilities properly. Like I said before, many PCs only allow have one DisplayPort connection to a Thunderbolt port. I don’t know if that’s true in your case.

All Macs have at least two DisplayPort connections per Thunderbolt controller. The M1 Mac is weird in that it also has two DisplayPort connections to a Thunderbolt controller/port but they can both be used only when a tiled display like the LG UltraFine 5K or Dell UP2715K is connected.

M1 GPU can have two displays (a normal display or a tiled display can be connected to Thunderbolt, the other display is the built-in display or HDMI port in the case of the M1 Mac Mini).

Intel GPU can have 3 displays.

Nvidia GPU can have 4 displays (I think there’s a trick that allows a tiled display to be connected as the last display – so that 5 total connections can be used in some cases).

AMD GPUs can usually have 6 displays.

What GPU is the Thunderbolt connected to? Maybe check the Device Manager, view by connection, find the display, and see what GPU is the parent device.

In your first post you said you had 3 monitors connected to the Thunderbolt 3 to Dual DisplayPort 1.2 adapter. How is that possible? Are you using an MST Hub or MST chaining? If the displays are connected to Intel GPU, including the built-in display, then you can only connect two external displays.

If your laptop has an Nvidia GPU, then why would the displays be connected to iGPU? I dunno. In the case of a Mac, the Intel GPU is used unless 3d acceleration is required or if external displays are connected. In that case, a MUX switches the internal display from iGPU (integrated) to dGPU (discrete). In a PC laptop, one possibility is that the dGPU will do rendering, but has to transfer the rendered content through iGPU to the display?

 

[joevt]

Some Thunderbolt ports don’t have two DisplayPort connections to a GPU.

What OS/computer/GPU/port/display are you using?

 

[joevt]

27MD5KA is the Thunderbolt only model. You need a 27MD5KL to do USB-C input.

With the 27MD5KL, 4K60 may be possible from the PS5. If there was a way to use a custom resolution on the PS5 and the PS5 supported 5K width, then 5K39 would be possible (but this is unlikely). I’m not sure if the 27MD5KL can accept 1080p. It does support 1440p.

 

[joevt]

The CSV-7300 is not a splitter. It is a DisplayPort 1.4 MST Hub. It allows connecting multiple displays to a single DisplayPort output. The GPU must do all the work of creating the streams that are to be output. Therefore, the only reason you would use the CSV-7300 is if your GPU doesn’t have enough outputs, which you say is true in your case.

An MST Hub can duplicate a single stream to multiple outputs. But since the streams are the same, they must have the same resolution and refresh rate. This feature is not what you want.

So the only way you can do what you want to do is use mirroring from the GPU to the display and capture card through the MST Hub. It should work but it uses additional resources of the GPU so there might be a slight performance difference.

I’m not sure how well mirroring works in Windows. In macOS, I can mirror to two 4K displays one at 60Hz and the other at 95Hz (not using MST Hub since macOS doesn’t support MST Hub).

Before you enable mirroring, try to get one display set to 120Hz and a second one set to 60Hz from the MST Hub. You need to get two separate displays working before you can try to mirror them. You might need to use CRU to create a custom resolution if the resolution you want is not available.

I guess first thing you should verify is that a display connected to the DisplayPort output is actually connected directly to the Nvidia GPU instead of the integrated Intel GPU. Check Device Manager and view by Connection Type.

Your laptop has Thunderbolt ports that support two displays but they may be connected to Intel GPU? Connect a display with a USB-C to DisplayPort adapter or cable and check Device Manager. A smart laptop like a MacBook Pro would connect Thunderbolt displays and internal display to the discrete GPU instead of the iGPU.

The iGPU in a Comet Lake CPU is limited to DisplayPort 1.2 so you’ll want to make sure it’s not being used for display output.

Normally an Nvidia GPU can output a max of 4 displays. Your laptop has 5 outputs though so I’m not sure what’s going on (two Thunderbolt, HDMI, DisplayPort, internal display). If you don’t have 5 displays to test, you can get inexpensive dummy adapters that fake a display.

An Intel GPU can connect 3 displays. I don’t know if there exist an laptops that will let you connect displays to both GPUs at the same time.

[joevt]

USB-C docks that don’t support USB 3.x (in other words, they support USB 2.0 only) can have four lanes of DisplayPort input. Such docks don’t need an MST Hub to support max resolution of 2560×1600 60Hz (or 4K 30Hz) from an HBR only adapter like the CAC-1010.

[joevt]

Even though the adapter is DisplayPort 1.2, it only supports max HBR link rate so it might work with a DisplayPort 1.1 GPU?

Since the adapter uses HBR link rate, it means it cannot do 2560×1600 60Hz from a USB-C dock (because USB-C docks only have two lanes of DisplayPort input) unless the USB-C dock includes an MST Hub (MST can convert two lanes of HBR2 or HBR3 to 4 lanes of HBR).

 

[joevt]

I think it exists (the Lontium LT6711GX) but no-one has made an adapter from it yet. More info in my forum post linked below (including why I think it would be good even for HDMI 2.0 and DisplayPort 1.2 ports)
https://insights.club-3d.com/thread/hdmi-2-1-to-usb-c-displayport-1-4-alt-mode/

 

[joevt]

The DSC that you want to use would be on the DisplayPort side. That would not be affected by the EDID since that info is in the DisplayPort DPCD.

There’s DSC info in the EDID for HDMI 2.1 (see the edid-decode project) but it’s not needed for 4K 120Hz which requires less than the 48 Gbps. Oh wait, above I said 4K 120Hz 12bpc 4:4:4 is 42.768 Gbps. HDMI 2.1 has a max of 42.67 Gbps (for 48 Gbps connection; 35.56 Gbps for 40 Gbps connection). So it seems DSC is required on the HDMI 2.1 side as well in that case. DSC is not required from HDMI 2.1 (40 or 48 Gbps) for 4K120 10 bpc 4:4:4 though.

[joevt]

I have used a CAC-1510-A to connect a 23 inch (Apple Cinema HD Display) and a 30 inch (Cinema Display) to a Mac mini 2018.

https://insights.club-3d.com/thread/2017-macbook-pro-with-30-apple-cinema-display/
https://forums.macrumors.com/threads/apple-cinema-display-30-driving-me-crazy-on-mac-mini-m1.2284953/post-29672865
https://forums.macrumors.com/threads/apple-cinema-display-30-driving-me-crazy-on-mac-mini-m1.2284953/post-29811958

[joevt]

I don’t think VESA certifies MST hubs.
https://www.displayport.org/product-category/cables-adaptors/

The CSV-7300 uses one of the Synaptics MST Hub chips (probably the VMM5330 or similar) which is used in many DisplayPort 1.4 MST Hubs.
https://www.synaptics.com/products/video-interface-ics

Some early DisplayPort 1.4 MST Hubs did not have the firmware to support DSC. Since the CSV-7300 advertises DSC support, one can assume that it has the latest firmware (or at least a version that has DSC support).
https://insights.club-3d.com/thread/displayport-1-4-mst-hub/
https://github.com/fwupd/fwupd/issues/1665

[joevt]

The AMD software tells you the link rate and lanes but it doesn’t tell you if DSC is supported and enabled. It would be helpful if the software reported more DisplayPort info from the DPCD registers like the AGDCDiagnose command does in macOS. The AMD software shows current link rate and lanes but doesn’t show supported link rate and lanes or the info about DSC. It doesn’t show info about MST hubs either (MST topology, etc.) or HDCP, etc.

I have a W5700 and I believe it supports DSC as I was able to use a MST Hub to connect three 4K displays at 4K 60Hz 8bpc RGB (that’s 533MHz pixel clock x 24bpp x 3 displays = 38 Gbps which is greater than the 25.92 Gbps that HBR3 can do without DSC (8.1 Gbps x 4 x 8b/10b).

The first screenshot in the AMD forum is using 4:2:0 chroma sub sampling which is a lossy compression method with a 2:1 compression ratio. (actually, it just throws away three quarters of the chroma components) 
1188 MHz pixel clock x 8bpc x 3bpc x 12c/24c = 14.25 Gbps.
1188 Mhz is the expected pixel clock for 4K 120Hz (4K 60Hz HDMI is 594 Hz and 120Hz is twice that).
DisplayPort HBR2 x4 is 5.4 Gbps x 4 x 8b/10b = 17.28 Gbps.
That means DSC is not being used.
HDMI 2.0b is 14.4 Gbps (6 Gbps x 3 lanes x 8b/10b) so it appears HDMI 2.1 is not being used.

The second screenshot in the AMD forum community post must be using DSC (a visually lossless compression method):
1188 MHz pixel clock x 12bpc x 3cpp = 42.768 Gbps.

Ok, so either the limit is HBR2 or HBR2 is being used because 4:2:0 is being selected with 8 bpc. You have to break the HBR2 barrier by switching to 12 bpc. That will get you into the HBR3 range. Then you need to break the HBR3 barrier by also enabling 4:4:4 to get into the HBR3+DSC range (required to get into the HDMI 2.1 range). None of that will be possible if a piece of the software thinks there’s a HDMI 2.0 barrier (because HDMI 2.0 has less bandwidth than HBR2 x4).

CRU could be used to remove the 4:2:0 options. I don’t know if that would get you into the HDMI 2.1 range though.

[joevt]

What is the exact model number of the 2020 Razer Blade 15 Base Edition?

If you are connecting to a Type A port, is it a port that actually supports USB 3.x? Does the port have four conductors or 8? What if you connect the WD passport directly to it without the hub?

Does the laptop have Thunderbolt? Use a Type C to Type A adapter to connect the hub. The Thunderbolt port will use a different USB 3.1 gen 2 USB controller. If it’s Alpine Ridge, then it will have its own USB 2.0 ports. If it’s Titan Ridge, then it may use the USB 2.0 ports of the chipset USB controller (the one we’re seeing now). If it’s Ice Lake or Tiger Lake (integrated Thunderbolt) then I’m not sure of the USB layout for Thunderbolt port – I would have to look around to find an example layout. Check the PCIe vendor and product ID of the USB controllers https://pci-ids.ucw.cz/read/PC/8086

If you had an external display, it might have a USB 3.0 connection.

[joevt]

A USB 3.0 hub always includes a USB 2.0 hub as well.

Connect a mouse or keyboard. The mouse should appear under a USB 2.0 hub.

Connect a USB 3.0 device such as a flash drive. It should appear under the USB hub. Both hubs should appear somewhere under the Intel USB 3.1 eXtensible Host Controller (click all the disclosure “>” buttons).

Maybe the Generic USB Hub is the USB 2.0 hub and the Unknown USB Device (Port Reset Failed) is the USB 3.0 hub, but that doesn’t make sense because you said it remains after the CSV-1430 is disconnected…

Do you have another computer to test the CSV-1430 with?

Maybe you need to update drivers? I use Driver Genius 21 to find new drivers for everything, but maybe you should start with your laptop’s website (but you said you had the latest drivers already).

 

[joevt]

What version of macOS?

Does SwitchResX show the 2560×1600 timing?

Post the result of the AGDCDiagnose command to pastebin.com or something.

[code]
/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > AGDCDiagnose_a.txt 2>&1
[/code]

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