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etc

macrumors regular
Sep 27, 2008
231
48
Hi there,

I have a Pro Display XDR now and was unable to get a DisplayPort based KVM Switch to work reliably.
I can switch from Mac to PC always, but never from PC to Mac - Display stays dark.
Ordered one very simple 8k capable USB C hub now (this one) and hope for the best.

The PC doesn't support thunderbolt, my plan is to connect it via a usb c to DisplayPort cable with the computers graphics card - any obvious flaw with this method? How did some of you get the brightness controls to work?
It just works. I assume your PC already has the USB-C DP port.

Brightness is controlled by the BootCamp software which can be installed using Brigadier:
 
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wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari

paulchiu

macrumors 6502
Feb 26, 2009
422
353
nyc
No, it is not… I thought it couldn’t be listed because it’s the least smart thing that Apple makes.

Is that relevant to getting it to work with a kvm?
I have used a powered KVM connecting my Pro Display XDR with several Macs, including this M3 Max MBP. Been running well for nearly a year now. I put a heat sink above the KVM to keep it running cooler.

Screenshot 2024-09-30 at 3.19.05 PM.png
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
I have used a powered KVM connecting my Pro Display XDR with several Macs, including this M3 Max MBP. Been running well for nearly a year now. I put a heat sink above the KVM to keep it running cooler.

View attachment 2430724
When I try to switch between a MacBook and Mac mini, that has also worked flawlessly - also from Mac to pc, but never back from pc to Mac. Display stays dark.
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
Okay, then you need this:
I have no pci slots left in the case - would have to get a motherboard with that function built in, or would have to use one of those cables that are usb c on one end, and then usb c, USB a and DisplayPort on the other
 

etc

macrumors regular
Sep 27, 2008
231
48
I have no pci slots left in the case - would have to get a motherboard with that function built in, or would have to use one of those cables that are usb c on one end, and then usb c, USB a and DisplayPort on the other
I'd recommend to use a cable instead of replacing a motherboard.
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
I'd recommend to use a cable instead of replacing a motherboard.
Yeah definitely… but right now, I’m getting the full resolution plus hdr with a simple usb c to DisplayPort cable;

How could it make a difference for the KVM switch if I have a working usb hub in the display or not?
 

etc

macrumors regular
Sep 27, 2008
231
48
Yeah definitely… but right now, I’m getting the full resolution plus hdr with a simple usb c to DisplayPort cable;

How could it make a difference for the KVM switch if I have a working usb hub in the display or not?
What kind of KVM you use? Does it have USB-C + DP outputs?
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
What kind of KVM you use? Does it have USB-C + DP outputs?
No, DP outputs only - so from the pc, I go DP <-> DP to the switch and DP <-> USB C to the display.

From the Mac, two bidirectional USB C <-> DP cables.

I have also tried a thunderbolt kvm, but that didn’t have a fallback mode to DP only, so didn’t work with the PC
 

etc

macrumors regular
Sep 27, 2008
231
48
No, DP outputs only - so from the pc, I go DP <-> DP to the switch and DP <-> USB C to the display.

From the Mac, two bidirectional USB C <-> DP cables.

I have also tried a thunderbolt kvm, but that didn’t have a fallback mode to DP only, so didn’t work with the PC

Okay, I see. I suppose you can't control brightness on both Mac and PC when you use this KVM?

Number 1: Ugreen

Number 2: TESmart
These are supposed to be used with regular DP displays. They usually use USB as a separate input if needed. But XDR uses a single TB/USB-C cable for both data and video signals. DP port provides video signal only, so even if you use DP to USB-C cable with your KVM, you get only a video signal and won't be able to control brightness or use XDR USB ports.

The solution here is the following:

1) You must use both USB (data) and DP (video) inputs with your KVM. Two cables must be connected from your PC or Mac to KVMs input #1 and #2 respectively;
2) You need to buy USB data + video mixer cable like this:

It must be connected to XDR and KVM USB (data) and DP (video) outputs.

This solution is a bit messy because it requires a lot of cables.

You can make it simpler with USB-C hub you already ordered:
1) Use a simple USB-C to USB-C cable to connect your Mac to the hub;
2) You still need a data + video mixer cable which I mentioned above to connect your PC to the hub (or directly to XDR if you want to test it).
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
Okay, I see. I suppose you can't control brightness on both Mac and PC when you use this KVM?


These are supposed to be used with regular DP displays. They usually use USB as a separate input if needed. But XDR uses a single TB/USB-C cable for both data and video signals. DP port provides video signal only, so even if you use DP to USB-C cable with your KVM, you get only a video signal and won't be able to control brightness or use XDR USB ports.

The solution here is the following:

1) You must use both USB (data) and DP (video) inputs with your KVM. Two cables must be connected from your PC or Mac to KVMs input #1 and #2 respectively;
2) You need to buy USB data + video mixer cable like this:

It must be connected to XDR and KVM USB (data) and DP (video) outputs.

This solution is a bit messy because it requires a lot of cables.

You can make it simpler with USB-C hub you already ordered:
1) Use a simple USB-C to USB-C cable to connect your Mac to the hub;
2) You still need a data + video mixer cable which I mentioned above to connect your PC to the hub (or directly to XDR if you want to test it).
Thank you!
I was able to control brightness from the Mac in this setup, and had hdr on both windows and Mac. I’m not too concerned with getting the displays usb hub to work yet, my issue is mostly why it would always allow me to switch from Mac to pc, but never back to the Mac.

I hope it works with this usb c switch…
 
Last edited:

paulchiu

macrumors 6502
Feb 26, 2009
422
353
nyc
When I try to switch between a MacBook and Mac mini, that has also worked flawlessly - also from Mac to pc, but never back from pc to Mac. Display stays dark.
Perhaps Sabrent made their thunderbolt 4 KVM primarily for the Mac OS market
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
Alright everyone…
Same result as always with a new usb c-based switch:

If I start everything from scratch, output from the Mac works.
Switching to windows works.

Switching back to the Mac does not.

Same as with all the other switches I tried in the past, so something is up. Switching between 2 Macs also works flawlessly.
 

wagninger

macrumors newbie
Sep 27, 2024
13
0
Bari
Okay, I see. I suppose you can't control brightness on both Mac and PC when you use this KVM?


These are supposed to be used with regular DP displays. They usually use USB as a separate input if needed. But XDR uses a single TB/USB-C cable for both data and video signals. DP port provides video signal only, so even if you use DP to USB-C cable with your KVM, you get only a video signal and won't be able to control brightness or use XDR USB ports.

The solution here is the following:

1) You must use both USB (data) and DP (video) inputs with your KVM. Two cables must be connected from your PC or Mac to KVMs input #1 and #2 respectively;
2) You need to buy USB data + video mixer cable like this:

It must be connected to XDR and KVM USB (data) and DP (video) outputs.

This solution is a bit messy because it requires a lot of cables.

You can make it simpler with USB-C hub you already ordered:
1) Use a simple USB-C to USB-C cable to connect your Mac to the hub;
2) You still need a data + video mixer cable which I mentioned above to connect your PC to the hub (or directly to XDR if you want to test it).
One question: I only find these mixer cables at 4k/60Hz, did this work for you or does yours explicitly state 8k?
 

etc

macrumors regular
Sep 27, 2008
231
48
One question: I only find these mixer cables at 4k/60Hz, did this work for you or does yours explicitly state 8k?
The bandwidth should indicated as 10 Gpbs or USB 3.1 Gen 2, everything else doesn't matter.
 

etc

macrumors regular
Sep 27, 2008
231
48
And then The display at full resolution, brightness controls and the usb hub on the back should work?
Yes, if it's connected to Mac. For PC you need to use any USB-C Muxer from the article I posted before.
 

Awakendi

macrumors newbie
Aug 1, 2024
7
0
Hi there! I encountered a strange problem, I have https://www.ebay.com/itm/144762539080
And the main problem is that this board in the usb controller does not see my XDR and there is no monitor in the bootcamp control panel. There is power on USB ports, but there is no data transfer. No matter what I connect to the usb of this card, windows 10/11 do not see devices. Please tell me, does the card turn out to be broken? What should I buy as a replacement? Thank you.
 

etc

macrumors regular
Sep 27, 2008
231
48
Hi there! I encountered a strange problem, I have https://www.ebay.com/itm/144762539080
And the main problem is that this board in the usb controller does not see my XDR and there is no monitor in the bootcamp control panel. There is power on USB ports, but there is no data transfer. No matter what I connect to the usb of this card, windows 10/11 do not see devices. Please tell me, does the card turn out to be broken? What should I buy as a replacement? Thank you.
I'd try the similar board from a different seller
 

Awakendi

macrumors newbie
Aug 1, 2024
7
0
I'd try the similar board from a different seller
Yes, I thought about it too. But I also thought if there were some settings in the bios that disable data transfer on this pci board. In any case, I will report on the results. Thank you, my friend.
 

Awakendi

macrumors newbie
Aug 1, 2024
7
0
What would you recommend me from these? I think you can buy a new one here.

 

etc

macrumors regular
Sep 27, 2008
231
48
Yes, I thought about it too. But I also thought if there were some settings in the bios that disable data transfer on this pci board. In any case, I will report on the results. Thank you, my friend.

I don't remember such settings in BIOS.

What would you recommend me from these? I think you can buy a new one here.

For me the cheaper one is better - more sales, lower the price. You can even buy two :)
 
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