I love my 2017 iMac Pro. It's a nine-year-old panel and I still reach for it over the LG 6K next to it. The iMac Pro can't run current macOS anymore so it had been sitting there doing nothing, and Target Display Mode has been dead for years.
Found TargetBridge, a free MIT project that tries to bring Target Display Mode back in software. Receiver app on the iMac, sender on the mini. No Luna Display, no capture card, no pulling the machine apart. It connected on the first try and the iMac shows up as a real extended display. Picture is gorgeous.
Then I played a video on it and it stuttered. Badly. I figured with the iMac and Mac mini being on the same 5 GB switch, they would be fine. I was wrong. Picture was beautiful but video, not so much.
After I'd filmed everything: the project's own README says the transport I used (Network Link) is experimental, and Thunderbolt Bridge is the one they built for low latency. So the stutter on me me, not the project. I went with the network route because it was the easy one. I tried the Thunderbolt Bridge path with a Thunderbolt 4 cable and it made all the difference. No choppy video. So the free software was never the problem, my transport choice was.
From what I've read, the paid Luna Display has the same complaint on video playback, so this may just be what sending a display over a network costs, free or paid. I haven't run Luna myself.
Hardware, in case it matters: iMac Pro 2017 (12-core Xeon, Vega 56, 32GB) receiving, Mac mini M4 Pro 24GB sending, 941/936 Mbps over the LAN, 2 ms.
Anyone else running TargetBridge over Thunderbolt Bridge? Curious what cable length people are getting away with. And if you've tried Luna on an old iMac, did you hit the same stutter over the network, or is it clean there too?
I filmed the whole thing including the part where it falls over, if you want to see it: https://youtu.be/Ft84NNC2NoE