LunaDisplay - MBP M1 Max to iMac 2020

[HaykD]

Hi!

I have an iMac 2020 and I'll soon get MBP M1 Max. Though I ordered LG UtraFine 5K monitor for my MBP, I've just found LunaDisplay and want to know:

1. Can I use LunaDisplay to connect MBP to iMac and use iMac as an external display?

2. What issues does this solution have? Is it the same experience as working from MBP to LG UltraFine or any other external display?

3. What other details I need to consider if I want to use Luna Display?

Thanks very much in advance.

 

[Tearabite]

I am in the same situation and have these same questions.

 

[joevt]

I believe the LunaDisplay adapter just fakes a connected display. The software does all the work. It uses the GPU/CPU to compress and transmit the data just like macOS's built-in screen sharing would.

As far as I know, there's no circuitry in the Luna Display adapter to take the DisplayPort signal, compress it, and transmit it. Maybe there's circuitry to act as a licence dongle?

I suppose the software makes it a little more seamless than using screen sharing so maybe that's where the value is.

If the LunaDisplay adapter does no work, then the question becomes:

Is sharing a display that is connected to the GPU more performant than sharing a virtual display created by something like BetterDummy ? Well, BetterDummy just creates a virtual display. You need some other software to do the sharing. So then the question is:

Is Luna's software better at sharing a GPU connected screen then someone else's software? What other options are there?

Duet appears to use the virtual display route with software on each end to do the work. Apple has or will have a similar feature in macOS.

DisplayLink is a hardware solution for sending data from USB 3.0 to a display. Software must be used to do the compression since USB cannot take 4K60 video uncompressed.

What I haven't seen is a hardware solution where all the work for the source video is done in the hardware. Well, there do exist video capture cards that could do that.

Is your iMac 2020 a 5K iMac? LunaDisplay says 5K can be supported up to 45Hz https://astropad.com/luna-display-5-1/
5K45 8bpc is similar in bandwidth to 4K60 10bpc which is the limit of DisplayPort 1.2.

 

[HaykD]

Yes, it is 5k, 27 iMac.

 

[yfaimac]

Yes I can confirm I have the same set up and it works. But latency is not perfect. I use the thunderbolt option to connect and for most things it is fine. But I wouldn't recommend it for actual video work or gaming.