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SDAVE

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Hey guys I have an OEM 6900XT that's working great in a 2019 Mac Pro connected to dual LG4k 27" monitors running at 4k via DisplayPort.

I know that TB3 isn't routed through since I took out the 580X (really horrible GPU btw).

Will there be a way for us with OEM GPUs to use the new Apple Studio Display? Specifically two of them.

I know Sonnet makes a GPU (probably with a different firmware) that allows to use the USBC port as TB3?

Or do we need to get the MPX module?
 

joevt

macrumors 604
Jun 21, 2012
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Hey guys I have an OEM 6900XT that's working great in a 2019 Mac Pro connected to dual LG4k 27" monitors running at 4k via DisplayPort.

I know that TB3 isn't routed through since I took out the 580X (really horrible GPU btw).

Will there be a way for us with OEM GPUs to use the new Apple Studio Display? Specifically two of them.

I know Sonnet makes a GPU (probably with a different firmware) that allows to use the USBC port as TB3?

Or do we need to get the MPX module?
The Sonnet 6900 XT has a USB-C port, not a Thunderbolt port. It supports USB-C DisplayPort Alt Mode, so connecting a display to it should work as long as the display doesn't require Thunderbolt.

The only Sonnet GPU that has Thunderbolt are their eGPUs that you connect via Thunderbolt.

I don't think anyone knows for sure if the Studio Display will work at 5K 60Hz using just a USB-C connection. I think it might be possible since the tech specs say it is compatible with the iPad Air (5th generation) which doesn't support Thunderbolt. The same goes for iPad Pro 11-inch (1st and 2nd generation) and iPad Pro 12.9-inch (3rd and 4th generation).
https://www.apple.com/ca/studio-display/specs/
If it doesn't work at 5K 60Hz then it should work at 4K 60Hz.

With a USB-C (not Thunderbolt) connection, the USB ports can only work at USB 2.0 speed (480 Mb/s) instead of USB 3.1 gen 2 speed (10 Gbps). You might want an MPX module in that case.

iPad Pro 11-inch (3rd generation) and iPad Pro 12.9-inch (5th generation) support Thunderbolt.
 
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goMac

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Apr 15, 2004
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I know Sonnet makes a GPU (probably with a different firmware) that allows to use the USBC port as TB3?

The Sonnet GPU only supports USB-C. But both the later model Ultrafine 5ks and Pro Display XDR can accept a USB-C signal.

USB-C can do 5k when display stream compression is supported by both the hardware and the monitor. The 6900XT supports it, but we don't know if the Studio Display does yet.
 

flowrider

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Nov 23, 2012
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I know Sonnet makes a GPU (probably with a different firmware) that allows to use the USBC port as TB3?

Others do too. The ones that come to mind are the Reference AMD cards and Gigabyte.

However if your card doesn't have a USB-C output you still have choices that will work with a TB3 display:

I have used both of these cable with success:


(But you lose the Brightness Control in the Display Preference Panel)

With cable you have full functional control over the Display PP:


Lou
 

SDAVE

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Others do too. The ones that come to mind are the Reference AMD cards and Gigabyte.

However if your card doesn't have a USB-C output you still have choices that will work with a TB3 display:

I have used both of these cable with success:


(But you lose the Brightness Control in the Display Preference Panel)

With cable you have full functional control over the Display PP:


Lou

So in theory, if 27" Studio Display supports USBC at 5k, we can use the Displayport to USBC adapter you posted to run at 5k60hz natively as @joevt and others mentioned?

Regarding monitor brightness, I currently have dual LG4ks vida displayport and use monitorcontrol and it works great natively with an apple keyboard :)
 

joevt

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Jun 21, 2012
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So in theory, if 27" Studio Display supports USBC at 5k, we can use the Displayport to USBC adapter you posted to run at 5k60hz natively as @joevt and others mentioned?
They work with the XDR so they should work the the Studio Display. Both the GPU and the display need to support DSC for 5K60.
 

flowrider

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Nov 23, 2012
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I forgot to mention another short coming of the bidirectional cable. The auxiliary USB ports on the back of the monitor will be dead.

The auxiliary ports on the back of the monitor will be active with the Belkin cable.

Lou
 
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SDAVE

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They work with the XDR so they should work the the Studio Display. Both the GPU and the display need to support DSC for 5K60.

Interesting so the correct DisplayPort to USB-C cable will work (DSC supported) especially if its dual monitors with a 6900XT at 5k60. That's good to know.
 

SDAVE

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I forgot to mention another short coming of the bidirectional cable. The auxiliary USB ports on the back of the monitor will be dead.

The auxiliary ports on the back of the monitor will be active with the Belkin cable.

Lou

It seems that the Belkin cable has USB2.0 cables so the auxilary ports like the 3 USB-C ports will run slower. I don't mind losing that as long as I have audio + video + webcam.
 

joevt

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Jun 21, 2012
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especially if its dual monitors
I don't know what this means.

It seems that the Belkin cable has USB2.0 cables so the auxilary ports like the 3 USB-C ports will run slower. I don't mind losing that as long as I have audio + video + webcam.
Right. There aren't many adapters that can do USB 3.x + DisplayPort 1.4 to USB-C conversion. A Thunderbolt 3 add-in card can do it, but then the display will connect as Thunderbolt. How to remove the Thunderbolt negotiation? A USB-C cable won't do that - it will just reduce the Thunderbolt connection to 20 Gbps (which is still enough for XDR 6K 60Hz using DSC). An HP Thunderbolt Dock G2 has a USB-C DisplayPort Alt Mode connector that can do the trick but this is only useful for testing since the HP Thunderbolt Dock G2 requires Thunderbolt which you would use for the Studio Display.

They won't be useful for the Studio Display unless it supports a USB-C DisplayPort Alt Mode with USB 3.x. Such a mode has only two lanes of DisplayPort.

You can do 5K 60Hz with HBR2 x2 using DSC@9bpp but macOS defaults to DSC@12bpp. Two lanes of HBR3 is enough for 5K 60Hz with DSC@12bpp which is exactly the same as what you would get with four lanes of HBR2.

You can try testing USB 3.x without DisplayPort. In that case only the USB-C ports will work. Use this test to see if it can do USB 3.x without Thunderbolt. Possibly the display won't even turn on?

You can try testing two lanes of DisplayPort with or without USB using a USB-C dock that has a DisplayPort output and doesn't include an MST hub. An MST hub would convert two lanes of DisplayPort to 4 which is not what you want to test.

But if you combine USB and DisplayPort, there's no way to force a two lane DisplayPort mode to get USB 3.x. Some displays have a switch to switch between USB 2.0 + DPx4 and USB 3.x + DPx2. But Apple displays don't have onscreen menus.
Maybe the Studio Display is smart enough to choose the USB 3.x mode if HBR3 is supported. But probably not.
 
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SDAVE

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I don't know what this means.


Right. There aren't many adapters that can do USB 3.x + DisplayPort 1.4 to USB-C conversion. A Thunderbolt 3 add-in card can do it, but then the display will connect as Thunderbolt. How to remove the Thunderbolt negotiation? A USB-C cable won't do that - it will just reduce the Thunderbolt connection to 20 Gbps (which is still enough for XDR 6K 60Hz using DSC). An HP Thunderbolt Dock G2 has a USB-C DisplayPort Alt Mode connector that can do the trick but this is only useful for testing since the HP Thunderbolt Dock G2 requires Thunderbolt which you would use for the Studio Display.

They won't be useful for the Studio Display unless it supports a USB-C DisplayPort Alt Mode with USB 3.x. Such a mode has only two lanes of DisplayPort.

You can do 5K 60Hz with HBR2 x2 using DSC@9bpp but macOS defaults to DSC@12bpp. Two lanes of HBR3 is enough for 5K 60Hz with DSC@12bpp which is exactly the same as what you would get with four lanes of HBR2.

You can try testing USB 3.x without DisplayPort. In that case only the USB-C ports will work. Use this test to see if it can do USB 3.x without Thunderbolt. Possibly the display won't even turn on?

You can try testing two lanes of DisplayPort with or without USB using a USB-C dock that has a DisplayPort output and doesn't include an MST hub. An MST hub would convert two lanes of DisplayPort to 4 which is not what you want to test.

But if you combine USB and DisplayPort, there's no way to force a two lane DisplayPort mode to get USB 3.x. Some displays have a switch to switch between USB 2.0 + DPx4 and USB 3.x + DPx2. But Apple displays don't have onscreen menus.
Maybe the Studio Display is smart enough to choose the USB 3.x mode if HBR3 is supported. But probably not.

Gotcha thanks, so all is not lost it seems. The W6900 MPX module is $6000 vs the $1300 I paid for the 6900XT OEM card. And I've been waiting for an Apple display for so long. I guess the best way is just to buy one and test it.

I mentioned dual monitors because that's how I always run my setup—always dual monitors. Definitely thinking of getting 2 of these bad boys (if 1 of them works well that is)
 

joevt

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Jun 21, 2012
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Definitely thinking of getting 2 of these bad boys (if 1 of them works well that is)
Ok. Connect one to the 6900XT's USB-C and another using Belkin Charge and Sync Cable (two such cables if the 6900XT doesn't have USB-C). That is the simplest method. Good luck. Let us know how it works out. Use AGDCDiagnose to verify that it's outputting 6016x3384 60Hz using DSC@12bpp. Or try my AllRez utility - both dump info to text.
 

SDAVE

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Ok. Connect one to the 6900XT's USB-C and another using Belkin Charge and Sync Cable (two such cables if the 6900XT doesn't have USB-C). That is the simplest method. Good luck. Let us know how it works out. Use AGDCDiagnose to verify that it's outputting 6016x3384 60Hz using DSC@12bpp. Or try my AllRez utility - both dump info to text.

So the USBC on the 6900XT (OEM, not from Sonnet) will work ? Mine has 1 port on it, it's the OEM AMD one from AMD.com
 

joevt

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Jun 21, 2012
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So the USBC on the 6900XT (OEM, not from Sonnet) will work ? Mine has 1 port on it, it's the OEM AMD one from AMD.com
I'm not sure about that. I know the USB controller of the W5700 works. But maybe the USB controller of the 6900XT doesn't work in macOS? I think I read something like that somewhere. In that case, you'll want to use a second Belkin Charge and Sync cable to get USB.
The tech specs for the 6900XT says a USB hub won't enumerate if you use the USB-C port. That could mean all the USB functions of the display won't work.
https://www.sonnettech.com/product/amd-radeon-rx6900xt-bundles/techspecs.html
 

flowrider

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Nov 23, 2012
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^^^^Yes, as I posted above:eek: The USB ports in the display will be dead with a bidirectional cable. They will be active with the Belkin cable.

Enough said❓

Lou
 

joevt

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Jun 21, 2012
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The USB ports in the display will be dead with a bidirectional cable. They will be active with the Belkin cable.
True. But I was talking about the USB-C port of the 6900XT which would only require a standard USB-C cable to work. If the USB-C port of the 6900XT doesn't work then the Belkin cable is the preferred alternative for connection to a DisplayPort port of the 6900XT.
 

flowrider

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Nov 23, 2012
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^^^^Actually a standard USB-C cable or a TB cable will not work. It needs to be a cable Like This:


AMHIK

And, even with a working USB-C cable, the USB ports on the monitor are still dead.

Lou
 

joevt

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Jun 21, 2012
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Actually a standard USB-C cable or a TB cable will not work. It needs to be a cable Like This:
I should have been more specific. I mean a cable like that which can do 10 Gbps USB or four lanes of 8.1 Gbps DisplayPort.
I don't consider a USB-C cable that only supports charging or USB 2.0 to be standard. Also, I don't think 100W PD is needed for a display signal.
 

DrEGPU

macrumors regular
Apr 17, 2020
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… Also, I don't think 100W PD is needed for a display signal.
it isn’t, but it is a useful proxy for finding good cables. Cables that support 100W PD tend to have all the features I’m looking for…
 

SDAVE

macrumors 68040
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Jun 16, 2007
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So has anyone tested with a 6xxx series graphics card and a simple USB-C cable to run at 5k60Hz on the Apple Studio Display?
 

ZombiePhysicist

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May 22, 2014
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Gotcha thanks, so all is not lost it seems. The W6900 MPX module is $6000 vs the $1300 I paid for the 6900XT OEM card. And I've been waiting for an Apple display for so long. I guess the best way is just to buy one and test it.

I mentioned dual monitors because that's how I always run my setup—always dual monitors. Definitely thinking of getting 2 of these bad boys (if 1 of them works well that is)

You could buy one 8k 65" display and have more space than the 2 monitors. :)

 

SDAVE

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You could buy one 8k 65" display and have more space than the 2 monitors. :)


Nah I'm good, I've been on dual monitors (specifically dual 27"'s) for the last 20 years and I don't plan on changing that anytime soon :)

I have tried them all.

Single 32"
Dual Ultrawide 38"
Dual 32"
Triple 27"
Single 40"

Nothing beats a V shaped dual 27" for me.

This is why dual Studio Displays is interesting to me. I loved the Thunderbolt and the older Apple studio displays (I've had almost all of them over the years) I'm not interested in HDR, as long as it's better than the iMac display im good. Right now I have dual LG UL850's and I like them, just wish they were a tad brighter.
 
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ZombiePhysicist

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May 22, 2014
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Nah I'm good, I've been on dual monitors (specifically dual 27"'s) for the last 20 years and I don't plan on changing that anytime soon :)

I have tried them all.

Single 32"
Dual Ultrawide 38"
Dual 32"
Triple 27"
Single 40"

Nothing beats a V shaped dual 27" for me.

This is why dual Studio Displays is interesting to me. I loved the Thunderbolt and the older Apple studio displays (I've had almost all of them over the years) I'm not interested in HDR, as long as it's better than the iMac display im good. Right now I have dual LG UL850's and I like them, just wish they were a tad brighter.

I used to have 6 30" cinema displays. :D

And I definitely preferred 3 30" cinemas in a wide U shape. The 30" right in front of you, and the other two leaves to the sides. That said, this is very subjective, and if that works best for you, that's all that counts! Many happy pixels to you!

As for brightness, my QN900A is so bright, I had to set it to just 10% brightness. 85" casts a LOT of light!
 

SDAVE

macrumors 68040
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Jun 16, 2007
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I used to have 6 30" cinema displays. :D

And I definitely preferred 3 30" cinemas in a wide U shape. The 30" right in front of you, and the other two leaves to the sides. That said, this is very subjective, and if that works best for you, that's all that counts! Many happy pixels to you!

As for brightness, my QN900A is so bright, I had to set it to just 10% brightness. 85" casts a LOT of light!

I used to have dual 30" cinema displays and that was too much haha.

Im very comfy with 27" and multiple desktops. CMD+TAB is my best friend.
 
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johnnymcc

macrumors regular
Jul 30, 2019
131
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Hey guys I have an OEM 6900XT that's working great in a 2019 Mac Pro connected to dual LG4k 27" monitors running at 4k via DisplayPort.

I know that TB3 isn't routed through since I took out the 580X (really horrible GPU btw).

Will there be a way for us with OEM GPUs to use the new Apple Studio Display? Specifically two of them.

I know Sonnet makes a GPU (probably with a different firmware) that allows to use the USBC port as TB3?

Or do we need to get the MPX module?
Unrelated, but DO NOT upgrade to 12.3 if you have a stock 6900 XT. That update has broken all Navi gpus. I have super-slow video playback now as if I have lost hardware acceleration. Apple's MPX modules appear to be fine.
 
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