connecting 2020 mbp 13" to 30" apple HD cinema display: will this work?

[uncleMonty]

First general question, I keep seeing in ads for USB-C adapters that they will work for MacBook Pro 2016-2019. Is this always just the manufacturer being late to update ad copy that they wrote in 2019, or are there really differences in the USB-C ports that make some adapters work for a 2019 MBP but not a 2020 model?

Second question more specific: the 10-yr-old display I still love, the 30" HD cinema display, has a dual-link DVI cable with an adapter that connected to my last laptop via one USB port and the mini display port. Will it work if I get a USB C to minidisplayport adapter (like this one: https://www.amazon.ca/Displayport-Answin-Thunderbolt-Adapter-2016-2019/dp/B07V828R4Q ) and a USB C->A adaptor, and use two of my 4 ports for this connection? (I realise a docking station with USB-A ports and a minidisplayport all built into the same hub would be nicer, but they are kinda expensive!)

I guess this second question has a general question built in: how is a person to know whether specific adapters can be strung together and still work?

 

[joevt]

First general question, I keep seeing in ads for USB-C adapters that they will work for MacBook Pro 2016-2019. Is this always just the manufacturer being late to update ad copy that they wrote in 2019, or are there really differences in the USB-C ports that make some adapters work for a 2019 MBP but not a 2020 model?

Second question more specific: the 10-yr-old display I still love, the 30" HD cinema display, has a dual-link DVI cable with an adapter that connected to my last laptop via one USB port and the mini display port. Will it work if I get a USB C to minidisplayport adapter (like this one: https://www.amazon.ca/Displayport-Answin-Thunderbolt-Adapter-2016-2019/dp/B07V828R4Q ) and a USB C->A adaptor, and use two of my 4 ports for this connection? (I realise a docking station with USB-A ports and a minidisplayport all built into the same hub would be nicer, but they are kinda expensive!)

I guess this second question has a general question built in: how is a person to know whether specific adapters can be strung together and still work?

If it works for 2019 then it works for 2020.

A USB-C to Mini DisplayPort adapter should work with the Mini DisplayPort to Dual Link DVI adapter that you already have.

You could try a USB-C to Dual Link DVI adapter which doesn't require a separate USB-A connection because the USB-C port has enough power for the DisplayPort to Dual Link DVI conversion.

StarTech.com USB 3.1 Type-C to Dual Link DVI-I Adapter - Digital Only - 2560 x 1600 - Active USB-C to DVI Video Adapter Converter (CDP2DVIDP), Space Gray

This USB-C to DVI adapter (digital only) lets you connect your USB Type-C device to any DVI display, including televisions and Apple Cinema HD Display and other DVI dual-link monitors. Ideal for Travel With its compact, lightweight design, this USB-C to DVI-I active adapter offers a convenient tr...

www.amazon.com

Club 3D | USB3.2 Gen1 Type-C to Dual Link DVI-D HDCP ON version Active Adapter M/F

The Club 3D CAC-1510 is a USB Type-C input to Dual Link DVI-D or Single Link DVI output adapter HDCP ON version for displays which do support HDCP. USB3.2 Gen1 Type-C to Dual Link DVI or Single Link DVI Adapter is the easiest solution for connecting your USB3.2 Gen1 Type-C source device...

www.club-3d.com

Usually adapters can be strung together but sometimes issues crop up if more than one adapter has to do some conversion. A USB-C to Mini DisplayPort adapter doesn't have to do any conversion. Here's an example of something that can have problems: say you have a HDMI 1.4 output and you want to connect a dual link DVI display to that - HDMI and DVI are the same except HDMI 1.4 can do single link up to 340 MHz while DVI is supposed to switch to dual link at 165 MHz (up to 330 MHz). To convert HDMI 1.4 single link to dual link DVI, you need to chain a HDMI 1.4 to DisplayPort adapter with a DisplayPort to dual link DVI adapter. This may work in some OS's better than others (because there's a connection detection issue that some OS's can deal with or ignore better than others).

 

[uncleMonty]

Thank you joevt for taking the time to reply and for giving straightforward answers to the questions asked. I'll try the cheaper option first rather than the USB-C to dual-link-DVI, even though it'll eat up two of my ports. Or more likely, I'll use one TB port for the USB-C to minidisplayport, and another TB port will have a USB-A multi-port which I'll use for the second part of the connection (along with other USB-A connections).

Which actually makes me think of another question: I was thinking of getting a mini-hub with ethernet and some USB-A ports like this one: https://www.amazon.ca/Anker-Unibody..._5?dchild=1&keywords=anker+usb+c+hub+ethernet -- will this allow me to pass power through the hub to USB-A peripherals that need it, like in my dual-DVI link setup above? I read that USB-C provides more than 3 times as much power as USB-A so I imagine I could pass enough power to three independent USB-A devices through a hub like this? (I see other hubs advertise power where this one doesn't, but I believe it's always referring to some hubs having power delivery *to* the laptop.)

 

[joevt]

Thank you joevt for taking the time to reply and for giving straightforward answers to the questions asked. I'll try the cheaper option first rather than the USB-C to dual-link-DVI, even though it'll eat up two of my ports. Or more likely, I'll use one TB port for the USB-C to minidisplayport, and another TB port will have a USB-A multi-port which I'll use for the second part of the connection (along with other USB-A connections).

Which actually makes me think of another question: I was thinking of getting a mini-hub with ethernet and some USB-A ports like this one: https://www.amazon.ca/Anker-Unibody..._5?dchild=1&keywords=anker+usb+c+hub+ethernet -- will this allow me to pass power through the hub to USB-A peripherals that need it, like in my dual-DVI link setup above? I read that USB-C provides more than 3 times as much power as USB-A so I imagine I could pass enough power to three independent USB-A devices through a hub like this? (I see other hubs advertise power where this one doesn't, but I believe it's always referring to some hubs having power delivery *to* the laptop.)

I don't think any adapters that take USB-A power follow the USB spec in asking for power (DisplayPort to Dual Link DVI adapters, HDMI to DisplayPort adapters, Wacom Link Plus DisplayPort/HDMI to USB-C adapter, etc.). The adapters will just take the power from the connection and the computer won't notify you that a device is asking for too much power. I wonder if a computer actually measures current draw on the ports? Maybe not. The computer could assume the devices are well behaved and won't take more power than they ask for.

I guess your computer won't melt if you try it.

 

[uncleMonty]

I don't think any adapters that take USB-A power follow the USB spec in asking for power

Really my question is more basic: will a USB-C to USB-A multiport allow devices connected to it to be powered by the laptop at all? I mean just the amount of power required to run the devices, not to charge them if they need charging, which I understand requires more power. For example I have an Apogee Duet audio interface that gets its power over USB... will that work if connected through a generic multi-USB hub? At the moment it's working fine with the new MBP, using a single Apple-brand USB-C to A adapter.

 

[joevt]

Really my question is more basic: will a USB-C to USB-A multiport allow devices connected to it to be powered by the laptop at all? I mean just the amount of power required to run the devices, not to charge them if they need charging, which I understand requires more power. For example I have an Apogee Duet audio interface that gets its power over USB... will that work if connected through a generic multi-USB hub? At the moment it's working fine with the new MBP, using a single Apple-brand USB-C to A adapter.

Yes, an unpowered hub should work fine. For example, I have an Apple keyboard with a mouse connected to it. The mouse works because the hub in the keyboard has enough power for the keyboard and the mouse.