Mac to Mac questions

I just purchased as USB-C module for use with the new Mac-to-Mac mode. My primary system is a MacBook Pro 15-inch 2018. My display is an iMac, Retina 5K, 27-inch late 2014. Both computers are using wired gigabit ethernet with WiFi disabled. I have a few issues / questions:

  1. The no retina option is presented when linking to the iMac. It is when I connect to an iPad instead.

  2. The display update is very slow, being pixelated for a bit before “focusing”. Remote desktop via VNC is much faster for comparison.

  3. I was hoping to control the MacBook and the iMac from the iMac keyboard and mouse. I can control the MacBook but is there a way to switch back to the iMac without exiting the secondary display application?

1 Like

I’m in a similar situation. I just purchased Luna to use my 2018 MacBook Pro 13" with my 2012 iMac 27", and while I think it’s quite usable, the pixellation when scrolling or paging through documents or switching browser tabs is noticeable. I’m connecting via wifi, so I guess my next route to try to improve the quality of the connection is to connect via USB, right? Oh, I see from the “Minimum Compatibility Requirements” at that USB isn’t allowed. So, the only supported method for improved latency is to connect the machines via Ethernet?

p.s. I just noticed that when mirroring displays, the keyboard and trackpad connected to the iMac work for typing and moving the cursor, even though the primary machine is the MacBook Pro. I didn’t have to do anything—it just worked. Very cool. The only oddity is that command-tab operates on the iMac, not the MacBook-driven screen. With display mirroring off, the keyboard still works (command-tab shows up on each display, but separately for the two machines; and holding down a letter doesn’t trigger repeated keypresses), but the trackpad is more quirky: it cannot control the cursor when it’s on the MacBook’s display. I’ll be interested to follow whether the developers are able to provide controls for more Mac-to-Mac scenarios like sharing of the secondary system’s keyboard and mouse.


To answer your questions:

  1. Retina support for iMacs is currently disabled as we ran into a few issues with it right before release. In a future update we’ll be adding support for 4K retina (we have it working in the lab now) and we are investigating 5k retina as well.

  2. I’m very surprised to hear that it’s slower than VNC for you even over ethernet! We’ve done most of our testing over wifi, so it’s possible we have a bug there. Could you take a video of the poor performance you are seeing? When you record the video, please have the Liquid Vitals visible on the iMac as well. You can show the Liquid vitals by going to the main Luna Display app and File Menu > Vitals. That would be hugely helpful in debugging this issue!

  3. Currently there isn’t a way to do this, you need to quit the Secondary app, We plan to add a way to minimize the Secondary app in the future which would do what you’re asking

I hope that helps!

I’m also getting decent pixelization on my iMac (as a secondary display), mainly when scrolling. I’ll agree with this post that is almost a step down from VNC. I was running my iMac in Target Display Mode and I’m a bit disappointed with the current latency with the Mac-To-Mac setup I’m using.

I took a screen recording of the issue happening with the vitals box visible too. Here it is:


Thanks for sharing this! I took a look at the video and the performance you’re seeing is what I’d expect on a typical wifi network. That being said, we are always looking to improve performance. We have a few ideas that we are experimenting with to improve scrolling performance in particular.

1 Like

If you were using WiFi on the video, IMO I would be say that you have a great performance. I don’t think this can be compared to VNC at any way.

Try scrolling a web page playing a video at 4K on your secondary screen on VNC, and then do the same with Luna… it simply can’t be compared.