[joevt]

What OS and GPU is the CSV-7000 connected to?

What displays are connected to the CSV-7000?

 

[joevt]

M-series Macs (Pro, Max, Ultra) support two displays per Thunderbolt port using Thunderbolt docks/hubs/displays up to the max total number of displays supported.

While the M1 Max only has 3 Thunderbolt ports, you can connect four displays to Thunderbolt if two are connected to the same Thunderbolt port (using a dock or hub or chaining in the case of Thunderbolt displays with two Thunderbolt ports).

M1 and M2 only supports one display from Thunderbolt ports but they do have a second DisplayPort connection to allow dual tiled displays such as the LG UltraFine 5K or Dell UP2715K to work at full resolution.

For M1 Max, you can connect 3 LG UltraFine 5K to Thunderbolt ports and an HDMI display, plus the internal display makes 8 DisplayPort connections total (HDMI uses a DisplayPort adapter; 3 of the DisplayPort connections are for the second tile of the LG UltraFine 5K displays and can’t be used for separate displays).

[joevt]

What about M1 Pro or M1 Max or M1 Ultra? club-3d docs seem to imply (by omission) that only Intel macOS doesn’t support MST.
https://www.club-3d.com/en/detail/2580/

As far as I know macOS for M-series Macs also doesn’t support MST but I have not tested this personally.

Intel and M-Series Macs can support DisplayLink but that has nothing to do with MST. I don’t think DisplayLink supports MST.

PowerPC and 68K Macs don’t support DisplayPort so of course those won’t support MST.

[joevt]

correction: CAC-1085+CAC-1336 can do 5K52 810.23MHz
Also, I was finally able to get 6K38 808.51MHz with the CAC-1085+CAC-1336
Maybe I need a GPU that can do DSC to get beyond the 811-820MHz boundary…

[joevt]

GTX 1070 is more of the same (Windows 10). 5K38 works. 6K doesn’t. Using 4:2:2 instead of RGB doesn’t increase the refresh rates allowed or working.

Then I tried connecting the CAC-1336 to a CAC-1085 and a DisplayPort 1.4 port. I can get 5K39 and 8K23 but still not 6K. I’m not sure what defines the limit of this connection. It’s between 787 and 822MHz (RGB 8bpc). I tried some 4K modes. CVT-RB2 didn’t work so I did CVT-RB which works up to 90Hz (811 MHz). 91Hz (820MHz) didn’t work.

I connected the display without adapters. Nvidia Control Panel now shows “G-SYNC Compatible”. 4K117, 5K68, 6K51, 8K30 (8K32 sort of works but the screen jiggles)
4:2:2 8bpc can increase refresh rate:

Greatest Mode Good Pixels: 4K130 1194.96, 5K76 1197.83, 6K55 1179.37, 8K34 1169.94
Least Mode with Bad Pixels: 4K131 1204.68, 5K77 1213.99, 6K56 1201.51, 8K35 1204.09
Greatest Mode Accepted: 4K142 1312.65, 5K83 1312.53, 6K61 1311.80, 8K38 1309.96
Least Mode Not Accepted: 4K143 1323.04, 5K84 1328.79, 6K62 1334.07, 8K39 1345.04

I don’t know why 4:2:2 would have mixed up pixels after 1200 MHz. It’s a problem with my display or Nvidia drivers.

I don’t know why the limit is between 1313 and 1323 MHz. DisplayPort 1.4 8bpc 4:2:2 limit is 1620 MHz. I suppose it’s related to the display’s 4K144 mode when two cables are connected (two tiles of 1920×[email protected] 632.01MHz x 2 = 1264 MHz).

[joevt]

To be clear, my CAC-1336 test with Radeon RX 580 should not count as a success with that setup (for non-VRR functionality). I only used that setup since it supported VRR from DisplayPort. See my thread CAC-1336 operation for more testing results.

[joevt]

Also stable with Nvidia Titan X (Maxwell), same setup as above. Tested in macOS High Sierra and Windows 10. I can get 5K38. 6K is broken like the Radeon RX 580. I had to use CRU to create EDID override since Nvidia Control Panel custom resolutions don’t work as well (same for Radeon Software).

Maybe the CAC-1336 won’t do 6K from HDMI 2.0? Or maybe the Radeon RX 580 and Nvidia Kepler / Maxwell HDMI 2.0 ports don’t support 6K. I can try Nvidia GTX 1070 (Pascal).

I am looking for results for other GPUs. Can they do 6K? Can any AMD GPUs produce a stable output? Maybe I should try an HDMI repeater for the Radeon RX 580…

[joevt]

Very stable results with Nvidia GTX 680 Mac Edition in macOS Monterey. CAC-1336 connected to HDMI 1.4 port. 4K30 works. 5K22 also works (CVT-RB but not CVT-RB2). I can’t try 6K from HDMI 1.4 since the display (Acer XV273K) can’t do less than 20Hz.

The Acer is connected to a CalDigit Element Hub which is connected to the CAC-1336 since the CAC-1336 doesn’t seem to like USB-C to DisplayPort adapters or cables.

[joevt]

For CAC-1336 notes, read my thread CAC-1336 operation

When it works, it does support USB 2.0 input. It might be more stable for Windows and Linux than macOS though.

 

[joevt]

I am thinking the CAC-1335 and CAC-1336 are more finicky then they should be. Read my post on the CAC-1336.  CAC-1336 operation

The fact that you can’t use adapters with them is bad especially the CAC-1336 – not being able to use a USB-C to DisplayPort cable or adapter is just wrong for a USB-C port…

Maybe you would have more luck if you put a Thunderbolt 4 hub between a CAC-1336 and your displayPort cable/adapters. The Thunderbolt controller might act like a DisplayPort repeater. It’s an awfully expensive solution, if it even works.

[joevt]

Seems strange that the CAC-1335 works with other displays but not the headset. What kind of cable is between the headset and the CAC-1335? Can it be replaced? The cable should not include any other adapters if possible.

[joevt]

The EDID has a 4320×2160 60Hz mode for HBR2 8bpc RGB/4:4:4 and a 90Hz mode for HBR3 8bpc RGB/4:4:4. There’s no 4:2:2 or 4:2:0 or DSC support. Both of those modes are in the DisplayID 1.3 extension block. The CTA-861 extension block only contains a Microsoft Vendor-Specific Data Block which identifies the device as a Virtual reality headset and assigns a UUID which I suppose can be matched with a UUID of a corresponding USB device for position tracking purposes. Does the headset have a USB connection?

Was the EDID from direct DisplayPort connection or was the CAC-1335 involved? Can you get an EDID with the headset connected to the CAC-1335? It will be interesting to see how the CAC-1335 affects the EDID. I think it might try to add a HDMI 2.1 Vendor-Specific Data Block.

For both connection types (from HDMI and DisplayPort) can you open Device Manager, view by connection, find the headset, and see if it’s attached to Nvidia or Intel GPU?

The EDID has 2880×1440 90Hz mode (428MHz) which is doable by HDMI 2.0 (limit 600 MHz). Did you try this mode?

 

[joevt]

I don’t think so.

Tested: CAC-1336, Radeon RX 580, Acer XV273K.

Windows 10: Freesync can be enabled from direct DisplayPort connection but not from HDMI 2.0 port and CAC-1336.

macOS 12.4: I think a newer GPU is require for VRR.

At least HDR works.

I don’t have a GPU with a HDMI 2.1 port.

[joevt]

[quote author="Leif45"]Apple Studio Display supports DisplayPort Alt Mode, and the Xbox Series X supports HDMI 2.1. I’m using the cable that came with the display.
Show more replies Liked by [/quote]

Do you have any other USB-C to USB-C cables to try?

[joevt]

It must be more than a signal quality problem if it can’t even do 25 MHz reliably. Actually, the signal coming out of the adapter is going to be using HBR3 anyway. But my display has a switch for DisplayPort 1.1 (HBR) DisplayPort 1.2 (HBR2) and DisplayPort 1.4 (HBR3) so I can try forcing HBR link rate  (allows 2560×1440 60Hz or 3840×2160 30Hz). I tried DisplayPort 1.1. There’s still weird flickering of pixels on the right edge of 720×576, 720×480, 640×480 modes. And the modes are still not stable. I also tried DisplayPort 1.2. I don’t have a way to test if the adapter is sending only an HBR or HBR2 or HBR3 signal.

[Author]

Posts