I like this discussion... I think Eric, et-al are correct from the standpoint of buffering, however there are issues I’ve found with poor Ethernet regarding noise, etc... I just finished a response to a recent discussion on streaming services which I believe applies to this discussion...And Ethernet bandwidth is usually NOT the issue. Here are parts of it which I believe apply.
.I had issues with streaming music versus the EXACT same album loaded on my Innuos ZENith MK3 with a Phoenix USB re-clocker feeding my Denafrips Terminator-Plus DAC. I use Qobuz which in my listening opinion sounds slightly better than Tidal. No matter what time of day though did streaming sound much better until I added in an Uptone-Audio EtherREGEN device between my Ethernet modem and the ZENith. Finally the music streamed was very close to that loaded onto the ZENith. I believe re-clocking the Ethernet signal with high-quality clocking and noise isolation from the EtherREGEN made all the difference no matter what time of day. It’s the most cost-effective $-for-$ I’ve spent for digital sonic improvement. My present cable internet service is ~300mbps. I will soon be going to fiber-optics with another ISP and their minimum service is ~500mbps. So, with this change I’ll know if anything improves, as I will keep both running and do a direct comparison before cancelling the cable service. I’ll let y’all know what I find ! In my opinion, I don’t think for audio you would need any more than what I have presently for internet speed as sonically the streamed music is extremely close (splitting hairs) to that stored on my music server. Finally, I understand about buffering and the moving of that data from the music-server to the DAC and theoretically it shouldn’t matter what’s going on upstream, however in practice, cleaning up the Ethernet signal in terms of noise, clocking and jitter obviously has made a difference in my system and listening. A positive thing for me that’s come out of this and a few other recent discussions is that I really need to look at the modem wall-wart as being a culprit in noise, etc. not only on the AC line, but in causing issues in the signal path as well... I have the modem wall-wart on a separate AC line from my listening space, but that doesn’t eliminate other signal-related anomalies created by it.