Caldigit TS4 Dock

[joevt]

The Caldigit TS4 doens't have a HDMI Port that's why I need an adapter (my monitor only has HDMI 2.1 ports). Not sure if I should use a Displayport or USB-C adapter to HDMI.

If you use USB-C to HDMI then you loose a USB-C port, so use DisplayPort if you can. They both have the same capability.
On the otherhand, a DisplayPort to HDMI 2.1 adapter might require a USB Type A connection for additional power. In that case a USB-C to HDMI 2.1 adapter would be simpler.

 

[chrfr]

The Caldigit TS4 doens't have a HDMI Port that's why I need an adapter (my monitor only has HDMI 2.1 ports). Not sure if I should use a Displayport or USB-C adapter to HDMI.

Personally I'd use the DisplayPort to HDMI adapter so I don't tie up a USB-C port.

 

[mario0]

Thank's for your input guys!
So I will try the USB-C to HDMI adapter. Actually it's not a problem for me to loose an USB-C Port.

 

[mattj88]

I'm using USB-C to USB-C. The cable came with the monitor. However, an HDMI cable (direct from Mac mini) also works.

Oh, gotcha. USBC on the monitor. Nice! I don't have any of those.

 

[mattj88]

The Caldigit TS4 doens't have a HDMI Port that's why I need an adapter (my monitor only has HDMI 2.1 ports). Not sure if I should use a Displayport or USB-C adapter to HDMI.

This is a problem with the TS4. So far, unexplainable. Depends. If you use the DP output on the TS4, You likely won't be able to get the Apple Retina Scaling options available in the display settings. This may not be an issue for you though. If you use the USBC to HDMI adapter, you will use up one of the TB4 ports on the TS4. Which sucks if you need that port for other TB4 accessories (like high speed drives).

Also, I'm working with the support team for Plugable brand cables and hubs right now....since CalDigit support is not good. Waiting days and days to get messages back. Plugable has detected a potential conflict between the Intel's Goshen Ridge Thunderbolt chipset that is in the TS4 and most other hubs, and DisplayPot HBR3 that exists in most USBC to HDMI adapters.

On the other hand, CalDigit is reporting a third and different behavior now, using their own branded adapters and cables...ugh.

 

[mattj88]

Personally I'd use the DisplayPort to HDMI adapter so I don't tie up a USB-C port.

Are you able to get the Apple Retina Scaling options in the display settings on the monitor you have connected via TS4 DP?

 

[mattj88]

Personally I'd use the DisplayPort to HDMI adapter so I don't tie up a USB-C port.

Or do you only see a pick list like this?

 

[EugW]

I get more scaling options using USBC than I do for HDMI.

Anyhow, if you want to see more scaling options (as in a list of resolutions), in Ventura it’s CTRL-click or else right click.

 

[chrfr]

Are you able to get the Apple Retina Scaling options in the display settings on the monitor you have connected via TS4 DP?

I don't recall what's there and I don't have access to a computer connected to the TS4 at the moment, but it doesn't really matter. The same resolutions are available in the list as you see in the "More space..." options.

 

[mattj88]

I don't recall what's there and I don't have access to a computer connected to the TS4 at the moment, but it doesn't really matter. The same resolutions are available in the list as you see in the "More space..." options.

Yeah, I just don't like it. I affects my workflow. I prefer to have the Retina thumbnail scaling options.

 

[mattj88]

I get more scaling options using USBC than I do for HDMI.

Anyhow, if you want to see more scaling options (as in a list of resolutions), in Ventura it’s CTRL-click or else right click.

Yeah, that's how it is designed, however, I ONLY get the long picklist of choices. I can't Option click and get it back to the thumbnail scaling choices when connected to DP.

 

[EugW]

Yeah, that's how it is designed, however, I ONLY get the long picklist of choices. I can't Option click and get it back to the thumbnail scaling choices when connected to DP.

Are you using Ventura? As mentioned, it's not option click in Ventura. It's CTRL-click or right click.

 

[mattj88]

Are you using Ventura? As mentioned, it's not option click in Ventura. It's CTRL-click or right click.

Weird. I'm on Monterey and it's an Option key click.

 

[EugW]

Weird. I'm on Monterey and it's an Option key click.

Yeah, they changed it in Ventura for some reason. However, I'm glad, since I think it makes more intuitive sense this way, and it also seems to me that the clicking is more consistent. In Monterey it was more picky as to where you had to put the cursor to get it to work.

 

[mattj88]

Yeah, they changed it in Ventura for some reason. However, I'm glad, since I think it makes more intuitive sense this way, and it also seems to me that the clicking is more consistent. In Monterey it was more picky as to where you had to put the cursor to get it to work.

Yes! I agree. And it is picky! Or at least it was. I had to click right inside the radio button. Can't click on the word "Scaled" next to the button. . For some weird reason...that is now working today. Weird.

 

[joevt]

This is a problem with the TS4. So far, unexplainable. Depends.

What's the problem? They don't have an HDMI output? I think that's a feature. You don't get stuck with the DisplayPort to HDMI adapter that they choose. You get to choose the adapter. And you can upgrade the adapter when a better one comes out.

If you use the DP output on the TS4, You likely won't be able to get the Apple Retina Scaling options available in the display settings.

A USB-C or Thunderbolt dock can only ever receive a DisplayPort signal from the host computer. It's a good thing the TS4 exposes the DisplayPort signal instead of mucking it up with an HDMI adapter. I'm not sure how it would be possible for a display that support DisplayPort and HDMI to have fewer options with a DisplayPort connection from a dock.

Plugable has detected a potential conflict between the Intel's Goshen Ridge Thunderbolt chipset that is in the TS4 and most other hubs, and DisplayPot HBR3 that exists in most USBC to HDMI adapters.

What is the behaviour that they see with Goshen Ridge that doesn't exist with Titan Ridge?
Only USB-C to HDMI 2.1 adapters use HBR3. HDMI 2.0 adapters only require HBR2.

On the other hand, CalDigit is reporting a third and different behavior now, using their own branded adapters and cables...ugh.

What behavior?

 

[mattj88]

What's the problem? They don't have an HDMI output? I think that's a feature. You don't get stuck with the DisplayPort to HDMI adapter that they choose. You get to choose the adapter. And you can upgrade the adapter when a better one comes out.


A USB-C or Thunderbolt dock can only ever receive a DisplayPort signal from the host computer. It's a good thing the TS4 exposes the DisplayPort signal instead of mucking it up with an HDMI adapter. I'm not sure how it would be possible for a display that support DisplayPort and HDMI to have fewer options with a DisplayPort connection from a dock.


What is the behaviour that they see with Goshen Ridge that doesn't exist with Titan Ridge?
Only USB-C to HDMI 2.1 adapters use HBR3. HDMI 2.0 adapters only require HBR2.


What behavior?

No. No HDMI output. Normally, I would agree, but the DP1.4 on the TS4 to DP1.2 on my monitor, prohibits the normal use of the MacOS Retina Scaling options (thumbnails). I use this for my normal workflow. EVERY single DP to HDMI adapter I tried (I tried a combination of 14 different cables and adapters) will not produce the Retina Scaling options.

I don't have an evidence that the display is limiting the options. I only have two monitors, both with HMDI 2.0 and DP 1.2 (Dell S3221QS). This is the case whether using DP directly from the Mac TB4 port or from the TS4 DP output.

The behavior is Apple's Retina Scaling display features (thumbnail options) are not available when using the DP connection (of any kind). The other issue is that when using two USBC to HDMI adapters, from the Mac directly OR from the TS4, I cannot get both monitors to display 4K@60Hz. The second monitor is always 30Hz. If I mix one adapter with one one-piece cable (USBC to HDMI), I am able to get both monitors @60Hz (the cables use a Parade PS186 chipset and the adapters use a Realtek RTD2172U chipset).

I don't have any knowledge of how a Titan Ridge chipset would behave, yet. Do you know which devices may be using this chipset? I could test them.

Plugable determined a potential problem with the Goshen chipset. Here is their response...
"...one of our specialists is investigating a potential issue with Intel's Goshen Ridge Thunderbolt chipset supporting dual 4K 60Hz displays with DisplayPort HBR3 (High Bit Rate version 3) adapters like the Plugable USBC-HDMI, the Plugable USBC-HDMI-CABLES should be unaffected as these are DisplayPort HBR2 devices. The HBR version determines the amount of bandwidth available for the external displays. HBR2 can support 4K 60Hz, while HBR3 is required for 5K 60Hz and 8K 30Hz resolutions.

The Plugable TBT4-HUB3C and from what I can tell the CalDigit docking station are both based on Intel's Goshen Ridge platform. We are not yet 100% sure what is causing this behavior and one of our specialists is currently investigating this issue. It also looks like mixing the HBR2 and HBR3 adapters will allow for 2x 4K60Hz displays in most cases ( with the TBT4-HUB3C at least ) and this tracks with what you have reported."

 

[mattj88]

Also, looks like DP uses MST and MacOS doesn't support that at all.

 

[joevt]

No. No HDMI output. Normally, I would agree, but the DP1.4 on the TS4 to DP1.2 on my monitor, prohibits the normal use of the MacOS Retina Scaling options (thumbnails). I use this for my normal workflow. EVERY single DP to HDMI adapter I tried (I tried a combination of 14 different cables and adapters) will not produce the Retina Scaling options.

I don't have an evidence that the display is limiting the options. I only have two monitors, both with HMDI 2.0 and DP 1.2 (Dell S3221QS). This is the case whether using DP directly from the Mac TB4 port or from the TS4 DP output.

The behavior is Apple's Retina Scaling display features (thumbnail options) are not available when using the DP connection (of any kind).

Which Retina options?
A 4K adapter should allow a 1920x1080 retina mode. Use SwitchResX to check for the 4K non-scaled mode and the 1920x1080 HiDPI mode?
A 4K adapter should allow a 2560x1440 retina mode. Use SwitchResX to check for the 5K scaled to 4K mode and the 2560x1440 HiDPI scaled to 4K mode?

The other issue is that when using two USBC to HDMI adapters, from the Mac directly OR from the TS4, I cannot get both monitors to display 4K@60Hz. The second monitor is always 30Hz. If I mix one adapter with one one-piece cable (USBC to HDMI), I am able to get both monitors @60Hz (the cables use a Parade PS186 chipset and the adapters use a Realtek RTD2172U chipset).

Plugable determined a potential problem with the Goshen chipset. Here is their response...
"...one of our specialists is investigating a potential issue with Intel's Goshen Ridge Thunderbolt chipset supporting dual 4K 60Hz displays with DisplayPort HBR3 (High Bit Rate version 3) adapters like the Plugable USBC-HDMI, the Plugable USBC-HDMI-CABLES should be unaffected as these are DisplayPort HBR2 devices. The HBR version determines the amount of bandwidth available for the external displays. HBR2 can support 4K 60Hz, while HBR3 is required for 5K 60Hz and 8K 30Hz resolutions.

The Plugable TBT4-HUB3C and from what I can tell the CalDigit docking station are both based on Intel's Goshen Ridge platform. We are not yet 100% sure what is causing this behavior and one of our specialists is currently investigating this issue. It also looks like mixing the HBR2 and HBR3 adapters will allow for 2x 4K60Hz displays in most cases ( with the TBT4-HUB3C at least ) and this tracks with what you have reported."

Connect the cable and adapter to an Intel Mac and run AllRez. It will tell you if they support HBR3 or HBR2.
If an adapter supports HBR3 and is connected first then the second adapter will be limited to HBR (4K30). AllRez will tell you what link rate and lanes each connection is using.
If you connect the HBR2 adapter first, then the HBR3 adapter should be limited to HBR2 so both can do 4K60.

I don't have any knowledge of how a Titan Ridge chipset would behave, yet. Do you know which devices may be using this chipset? I could test them.

Any Thunderbolt 3 device that supports DisplayPort 1.4 HBR3 link rate.

Also, looks like DP uses MST and MacOS doesn't support that at all.

macOS doesn't support MST for connecting multiple displays to a single DisplayPort output, but it can use MST for converting HBR link rate and number of lanes. For example, a DisplayPort 1.4 MST hub can convert 2 lanes of HBR3 to 4 lanes of HBR2. I suppose you could connect a DisplayPort 1.2 MST hub to force 4 lanes of HBR3 to 4 lanes of HBR2.
AllRez output from an Intel Mac will tell you if an adapter or dock is using MST and if DSC is supported.

 

[mattj88]

Thanks for the reply again.

Which Retina options?

The feature that allows you to select your scaling via thumbnail icons, instead being forced to select them via a dropdown pick list. I was told by the Plugable support team - this is called Retina Scaling. Any DP connection made from the TS4, whether it's direct to a DP connection on a monitor or to a DP to HDMI adapter I've tried, always results in the scenario that forces yo to use the pick list. You can't Option key click (OS Monterey) the radio button and get the option to use the thumbnail icons.

A 4K adapter should allow a 1920x1080 retina mode. Use SwitchResX to check for the 4K non-scaled mode and the 1920x1080 HiDPI mode?
A 4K adapter should allow a 2560x1440 retina mode. Use SwitchResX to check for the 5K scaled to 4K mode and the 2560x1440 HiDPI scaled to 4K mode?

Ok, I'll give these a shot. Thanks!

Connect the cable and adapter to an Intel Mac and run AllRez. It will tell you if they support HBR3 or HBR2.
If an adapter supports HBR3 and is connected first then the second adapter will be limited to HBR (4K30). AllRez will tell you what link rate and lanes each connection is using.
If you connect the HBR2 adapter first, then the HBR3 adapter should be limited to HBR2 so both can do 4K60.

I don't have an Intel based Mac. Is there a similar feature for Silicon Macs?
Why is the second adapter limited to HBR only if both adapters support HBR3?
I do get both HBR2 cables to support 4K@60HZ. Why not the 2 HBR3 adapters? Aren't those higher bandwidth? Too much for another part of the system.

Any Thunderbolt 3 device that supports DisplayPort 1.4 HBR3 link rate.

Ok. Perhaps that could be the problem then. Maybe it's the display itself. The TS4 supports DP1.4, and the cables I tried were DP1.4, but the monitor will only support DP1.2. However, I don't have an issue with HDMI 2.0 on the monitor.

macOS doesn't support MST for connecting multiple displays to a single DisplayPort output, but it can use MST for converting HBR link rate and number of lanes. For example, a DisplayPort 1.4 MST hub can convert 2 lanes of HBR3 to 4 lanes of HBR2. I suppose you could connect a DisplayPort 1.2 MST hub to force 4 lanes of HBR3 to 4 lanes of HBR2.
AllRez output from an Intel Mac will tell you if an adapter or dock is using MST and if DSC is supported.

Interesting. I think I get that...I can actually get 4K60Hz from the DP1.4 on the TS4 to DP1.2 on my monitor, I just don't get those nice thumbnail options for scaling.

 

[joevt]

I don't have an Intel based Mac. Is there a similar feature for Silicon Macs?

I would need a Apple Silicon Mac to try some experiments to create the code that can get the information on Apple Silicon Macs. The required APIs for Apple Silicon Macs are not documented. MonitorControl.app has source code for doing DDC/CI. They had to figure that out without Apple's help. I suppose the same thing can be done for DisplayPort aux channel communication to get DPCD info.

Why is the second adapter limited to HBR only if both adapters support HBR3?
I do get both HBR2 cables to support 4K@60HZ. Why not the 2 HBR3 adapters? Aren't those higher bandwidth? Too much for another part of the system.

Thunderbolt is 40 Gbps. HBR is 8.64 Gbps. HBR2 is 17.28 Gbps. HBR3 is 25.92 Gbps. So you can get HBR2 + HBR2 or HBR3 + HBR but not HBR3 + HBR3.

macOS has a trick for getting HBR3 + HBR3 for the Apple Pro Display XDR to get 6K60 10bpc from GPUs that don't support DSC but macOS does not apply this trick for anything else. Windows and Linux do not allow the same trick.

The HBR3 + HBR3 trick works with 6K60 (actually dual 3008x3384 60Hz) because Thunderbolt does not transmit the DisplayPort stuffing symbols that DisplayPort uses to fill up the DisplayPort bandwidth. Each 3008x3384 tile only requires 19 Gbps instead of the full 25.92 Gbps of HBR3.

DSC reduces bpp (bits per pixel) from 36 to 12 so it's possible to do 6K60 12bpc (bits per component) using just a HBR2 connection and in fact 6K60 12bpc with DSC takes less bandwidth than 4K60 10bpc without DSC.

Ok. Perhaps that could be the problem then. Maybe it's the display itself. The TS4 supports DP1.4, and the cables I tried were DP1.4, but the monitor will only support DP1.2. However, I don't have an issue with HDMI 2.0 on the monitor.

DP1.2 (HBR2) has more bandwidth than HDMI 2.0 so it should be the better option.

Interesting. I think I get that...I can actually get 4K60Hz from the DP1.4 on the TS4 to DP1.2 on my monitor, I just don't get those nice thumbnail options for scaling.

I usually use SwitchResX so I don't have to deal with Apple's low information UI.

 

[mattj88]

I would need a Apple Silicon Mac to try some experiments to create the code that can get the information on Apple Silicon Macs. The required APIs for Apple Silicon Macs are not documented. MonitorControl.app has source code for doing DDC/CI. They had to figure that out without Apple's help. I suppose the same thing can be done for DisplayPort aux channel communication to get DPCD info.

Ok. I don't have a spare one at the moment, but I am looking for a Macbook Air to supplement my workflow. If I can get one used for a deal, I could send it to you for a bit.

Thunderbolt is 40 Gbps. HBR is 8.64 Gbps. HBR2 is 17.28 Gbps. HBR3 is 25.92 Gbps. So you can get HBR2 + HBR2 or HBR3 + HBR but not HBR3 + HBR3.

Interesting, so in theory, if I found two USBC to HDMI adapters that were both only HBR2, that would solve the issue? Why can't you force an HBR3 adapter to work at HBR2?

macOS has a trick for getting HBR3 + HBR3 for the Apple Pro Display XDR to get 6K60 10bpc from GPUs that don't support DSC but macOS does not apply this trick for anything else. Windows and Linux do not allow the same trick.

Oh nice! Sadly, I don't have any of those monitors, though it looks like I might be due to upgrade one of my monitors for color correction.

The HBR3 + HBR3 trick works with 6K60 (actually dual 3008x3384 60Hz) because Thunderbolt does not transmit the DisplayPort stuffing symbols that DisplayPort uses to fill up the DisplayPort bandwidth. Each 3008x3384 tile only requires 19 Gbps instead of the full 25.92 Gbps of HBR3.

DSC reduces bpp (bits per pixel) from 36 to 12 so it's possible to do 6K60 12bpc (bits per component) using just a HBR2 connection and in fact 6K60 12bpc with DSC takes less bandwidth than 4K60 10bpc without DSC.


DP1.2 (HBR2) has more bandwidth than HDMI 2.0 so it should be the better option.

Oh Wow! I have a bit to learn. I wondered about the bandwidth of the DP1.2 vs HDMI 2.0. One of the adapters I just bought from CalDigit to test says it's HDMI 2.0b? What is the "b" in this case?

I usually use SwitchResX so I don't have to deal with Apple's low information UI.

I just downloaded that software. Looks thorough. I will have to play around with it.

 

[chrfr]

Are you able to get the Apple Retina Scaling options in the display settings on the monitor you have connected via TS4 DP?

This is what I see in the Settings app when using the TS4 connected to an M2 Air or a 2018 13" MBP, both running macOS 13.1. The display is an LG 24UD58-b connected to the TS4 via a Caldigit DisplayPort to HDMI adapter.

 

[mattj88]

This is what I see in the Settings app when using the TS4 connected to an M2 Air or a 2018 13" MBP, both running macOS 13.1. The display is an LG 24UD58-b connected to the TS4 via a Caldigit DisplayPort to HDMI adapter.

Nice! What DP to HDMI adapter are you using? What HDMI cable?

 

[chrfr]

Nice! What DP to HDMI adapter are you using? What HDMI cable?

It's Caldigit's adapter, likely this one: https://shop.caldigit.com/us/index.php?route=product/product&product_id=175

I have no idea what the cable is. It's just a standard ~1m cable that supports 4k/60.