Review on 🎮 UCEC GAM Live Ultra 4K60 Capture Card with HDR10, RGB, Lossless Video Recording, 240FPS High Refresh Rate, Zero-Lag Passthrough, Ultra-Low Latency Streaming, for PS5, PS4, Xbox Series X/S, Xbox, USB 3.0 by Jerry Leon

I was trying to use this to record video from Windows PC to iMac because Apple removed the target display mode (video input). This shot is probably the best you can do with low latency today. I measured 100-200ms at 5k with OBS. Using QuickTime was 100ms faster but the resolution was 1920x1080. In the end I didn't find a setting I liked as 1920x1080 is too low a resolution with reasonable latency. But 5120x2880 was too laggy for me in OBS. I wish there was a native capture setting for 2160x1440, but there isn't.