Extend your long-distance PC connection to the upper floor.
Extend your long-distance PC connection to the upper floor.
I think it’s based on the Pi 3B+ data stating "Gigabit Ethernet over USB 2.0 (max 300 Mbps)" while the Pi 4B only lists "Gigabit Ethernet." This suggests the Pi 4B might not face the same speed cap, making 300 Mbps sufficient for smooth streaming. I’m not sure why it seemed limited at first, but 300 Mbps should handle a solid 1080p60fps video.
It's possible the processor struggles to process the live stream quickly enough.
Use a USB3 connection instead of the SD card for faster performance. Switch your installation to run via USB3 with an SSD connected through a USB adapter. For maximum speed, consider a 5V USB cooler for the Pi.