Ah ok, you're referring to the sample rate. Either way, it still wouldn't come close to maxxing out the usb bandwidth.Ahh yes, apologies, what I mean by "bandwidth" is that SPDIF is limited to 24bit/192kHz, whereas USB can support up to 32 bit/768 kHz. The maximum communication throughput is totally irrespective of the audio file size. USB can support digital formats like native DSD for instance, whereas SPDIF has limited support (i.e. only DSD over PCM). Just one example...
And when you say that USB is "very noisy," what are you basing this on, exactly? Because from what I have seen, USB usually offers lower jitter, and ultimately less noise and distortion than SPDIF. Example--
https://www.thewelltemperedcomputer.com/Intro/SQ/USB_SPDIF.htm
In fact, if you follow Amir's posts on ASR, he demonstrates this fact regularly when he evaluates the noise and disortion coming from various DAC's inputs. So, I'm curious to learn where you are seeing SPDIF so routinely outperforming USB.
I think spdif is limited to dsd64 if I'm not mistaken but i2s can support higher levels of DSD. There are alot of people that don't like oversampling and will tell you that NOS sounds better. I prefer dsd upsampling but thats just me.
This may ruffle some feathers but what the hey. When I say noisy, I'm referring to electromagnetic interference. This is a sensitive subject because there are people who don't believe such a thing exists.
PC components like the cpu, ram, gpu, PS, etc, are very noisy, they generate noise and spread it around everywhere including into your audio system. Basically, anything that carries an electrical signal, has an EMF around it, and it moves with the flow of power. Most things are not affected by this noise but audio is very sensitive to this noise and on top of that its difficult to hear when its mixed in with music. If you play some white noise mixed in with your music, it'll be extremely difficult to isolate it by ear, most people won't even notice its there. However, once its removed, its very easy to tell as the sound improves.
I didn't say anything about spdif outperforming anything.
Amir is an amusing character, example, he reviews and judges the sound quality of audio devices without using his ears. It'd be the equivalent of a TV reviewer that refuses to look at the TV and only rates it based on measurements.
His methodology is quite silly, he measures the same metrics for devices that operate differently. All tube amps measure poorly, does that mean all tube amps don't sound good?
“If it measures good and sounds bad, — it is bad. If it sounds good and measures bad, — you've measured the wrong thing.” - Daniel von Recklinghausen
This doesn't really apply to amir since he doesnt use his ears at all.