Two computers and one Studio Display?

[joevt]

dscTargetBPP is definitely the correct name and case. It exists in CoreDisplay for Catalina, Big Sur, and Monterey. I guess I need to do more digging to see how it's used. I wish this part was still open source. InstallTiming functions (including scaled resolutions) were last seen in HighSierra 10.13.6 open source code (IODisplayLib.c) which predates DSC support. The timing and scaled modes functions were moved to CoreDisplay starting with Sierra 10.12.

Turns out that the dscTargetBPP preference can only be changed if the Apple Internal SIP bit is set, and that bit cannot be set by csrutil. I don't know how to change that bit.

My WhateverGreen fork (Intel Macs only) has a new patch to change dscTargetBPP (add a boot-arg dscbpp=8 - for Catalina and later). If you're using Open Core or OCLP, then you can replace Lilu and WhateverGreen with my versions. If you use any other Lilu based kexts then they need to be recompiled using the headers from my Lilu.kext. That patch, in conjunction with the CheckTimingWithRange patch (add a boot-arg -cdfon - For Tiger and later), can enable 4K240 and beyond on Intel Macs with a GPU that supports DSC (tested with 6800XT and Sequoia). DP to HDMI adapters are not tested.

I think Apple Silicon Macs automatically support DSC with values ≤ 12 (4K240 tested on M3 with Sequoia).

 

[petardosh]

I found this interesting on the support page from Cable Matters for their new USB4 switch:

Cable Matters is currently developing a 40Gbps USB-C switch that is expected to offer full Thunderbolt 3 support, providing enhanced compatibility for all USB-C devices. This upgrade will allow users to take advantage of higher data transfer speeds and improved video performance with USB-C monitors and peripherals.

Maybe this will be finally the switch that supports the XDR at full resolution without DSC and USB3 speeds for its USB hub.

 

[Jonesy99]

Assuming the machines are on the same network and have a fast connection, why not use Moonlight/Sunlight or Parsec and stream one machine through the other - no monitor switching required.

 

[Jonesy99]

Assuming the machines are on the same network and have a fast connection, why not use Moonlight with NVidia Game Stream and stream one machine through the other - no monitor switching required. I do this with my gaming PC through my MacBook and get 60FPS on my Apple Studio Display. I can literally swipe backwards and forwards between my Mac and PC at full resolution.

 

[StefanK.]

I found this interesting on the support page from Cable Matters for their new USB4 switch:



Maybe this will be finally the switch that supports the XDR at full resolution without DSC and USB3 speeds for its USB hub.

I bought the Cable Matters USB C switch (link to german amazon) to use my new Studio Display with my Mac Studio and my wife's Windows laptop without having to replug the thunderbolt cable all the time. And it works perfectly!

On windows, it supports up to 4K 60Hz (which is fine for her) and the speakers, mics and camera all work. The resolution might also be a limitation of the AMD Ryzen 3 based APU. It works via Display Port Alt Mode, her laptop does not have Thunderbolt.

And on my Mac Studio it works at a full 5K 60Hz. But I had to use the included cables, the thunderbolt cable from the Studio Display did not work. I am no expert of ports, cables and protocols. If I had to guess, I would assume that when using the thunderbolt cable to connect to the switch, the Mac tries to go into "thunderbolt mode" which is not supported by the switch. But when I use the included cables, it also falls back to Display Port via USB C. Not sure how, but it supports 5K.

The switch also stays cool, makes zero noise when switching between devices and I have had zero issues in the first week. Let me know, if someone is interested in more details.

 

[petardosh]

@Jonesy99 Thanks I wasn't aware of these. I have a work and private laptop and would like to keep things separate at the hardware level.

@StefanK. The current Cable Matters switch is probably good enough for most applications. I do have Apple Pro Display not a Studio Display, that's why I prefer to wait for a true Thunderbolt 3 switch that can support the Pro Display at native resolution without DSC or limiting the speed of its built-in USB3 hub.

 

[ad6922]

I bought the Cable Matters USB C switch (link to german amazon) to use my new Studio Display with my Mac Studio and my wife's Windows laptop without having to replug the thunderbolt cable all the time. And it works perfectly!

On windows, it supports up to 4K 60Hz (which is fine for her) and the speakers, mics and camera all work. The resolution might also be a limitation of the AMD Ryzen 3 based APU. It works via Display Port Alt Mode, her laptop does not have Thunderbolt.

And on my Mac Studio it works at a full 5K 60Hz. But I had to use the included cables, the thunderbolt cable from the Studio Display did not work. I am no expert of ports, cables and protocols. If I had to guess, I would assume that when using the thunderbolt cable to connect to the switch, the Mac tries to go into "thunderbolt mode" which is not supported by the switch. But when I use the included cables, it also falls back to Display Port via USB C. Not sure how, but it supports 5K.

The switch also stays cool, makes zero noise when switching between devices and I have had zero issues in the first week. Let me know, if someone is interested in more details.

@StefanK, saw your message and just ordered the switch. I hope that your experience is still that good since you post this.

 

[mcewen98]

To recap... it sounds like the 2 options to make my LG Ultrafine 5k work with both my M1 Mac mini and my M1 MBP are either 1) This cheaper $40-$60 option that's sold under various names: amazon, Newegg, or 2) The $300 Sabrent KVM

It sounds like there are examples of people using both successfully with a single display shared to multiple machines.

My setup is a bit more complex. I want to have 3 displays total, with the left display dedicated to the Mac mini and the right display dedicated to my MBP. I want the middle display to be selectable and work with either.

Has anyone tried this setup with either of the options? Can anyone confirm if monitor arrangement is preserved when switching machines that have multiple displays connected?

The comments on the cheap option on Amazon mentions EDID is not supported so arrangements may get reset when switching. If The Sabrent KVM preserves monitor arrangements I might be able to justify the cost.

Thanks!

 

[StefanK.]

@StefanK, saw your message and just ordered the switch. I hope that your experience is still that good since you post this.

@ad6922 yep, still working great!

 

[StefanK.]

To recap... it sounds like the 2 options to make my LG Ultrafine 5k work with both my M1 Mac mini and my M1 MBP are either 1) This cheaper $40-$60 option that's sold under various names: amazon, Newegg, or 2) The $300 Sabrent KVM

It sounds like there are examples of people using both successfully with a single display shared to multiple machines.

My setup is a bit more complex. I want to have 3 displays total, with the left display dedicated to the Mac mini and the right display dedicated to my MBP. I want the middle display to be selectable and work with either.

Has anyone tried this setup with either of the options? Can anyone confirm if monitor arrangement is preserved when switching machines that have multiple displays connected?

The comments on the cheap option on Amazon mentions EDID is not supported so arrangements may get reset when switching. If The Sabrent KVM preserves monitor arrangements I might be able to justify the cost.

Thanks!

Do you want 3 studio displays?
Because the Mac mini only supports a second screen at a maximum of 4K via HDMI.

 

[mcewen98]

Do you want 3 studio displays?
Because the Mac mini only supports a second screen at a maximum of 4K via HDMI.

I should have mentioned in my first comment. The current M1 Mac mini is about to be replaced with a M4 Pro mini. I want to drive 2 LG Ultrafine 5k displays with 2 of its TB5 ports. Then I want to share 1 of those 5k displays with my MBP (M1 Pro) which also has its own 4k display.

I should probably just buy the one on amazon and see if it will work, return it if not. I just don't want monitor arrangement to be an issue. I had to go into display settings every time I switched the LG 5k from the mini to the MBP and reset the monitor positions then that would be too annoying to deal with.

 

[ad6922]

@StefanK. received it yesterday and yes, works great. Thanks for sharing as I have searched quite a while for a product like this.

 

[mcewen98]

I received the Amazon option yesterday and I think it will work fine, even with my built in LG webcams. My only complaint so far is about the cables it comes with. They are short, cheap, and don't bend easily. I also found that my LG display cables, nor my expensive Apple Thunderbolt cable will work with it. It only seems to work with the cables it came with.

I would be completely happy if the cables were about twice as long so that I could mount it in a convenient location.

Has anyone found a better cable option that works with it?

 

[RyanC1384]

My setup:

M3 Macbook Pro (Work)
M4 MacMini (Home)
(2) Apple Studio Displays
CalDigit TS4 Dock

Can someone recommend a solution for me to easily switch between the 2 computers and allow for both studio displays and peripherals to work seamlessly?