I don’t have two great devices to test with but my bet is on the CPU being the bottleneck. I have only used the feature between my desktop (5900x, 2,5 gigabit connection) and a steam deck (a comparably bad CPU, 1 gigabit ethernet or WiFi)
The steam deck also caps at around the same speed when downloading from the internet while the desktop can download at near 2,5 Gigabit speeds.
I don’t have two great devices to test with but my bet is on the CPU being the bottleneck. I have only used the feature between my desktop (5900x, 2,5 gigabit connection) and a steam deck (a comparably bad CPU, 1 gigabit ethernet or WiFi)
The steam deck also caps at around the same speed when downloading from the internet while the desktop can download at near 2,5 Gigabit speeds.
Oh and both devices used NVME drives.
The CPU on the source used for compression is definitely the bottleneck for me. Internet is faster.