thanks Zoom what a great response! My dealer from Calgary got me on to Roon using my iMac in another room. From the modem I’m wired via Ethernet cord I said from the beginning hard wired always sounds better. Wrong, boy I was wrong he was so right about wifi transferring. I had a portable drive into my Pi first and it sounded great. Roon wifi into the Pi is a step above that, now would a better sound card be sonically ahead vs the Pi?
I’ve never lagged even with MQA and HD transfers
If I had to speculate, I'd imagine the full sized BDPs to sound better than the Pi. The Pi has a coaxial, hdmi, usb, and optical output, whereas the full sized BDP have AES, coax, along with USB. I'm guessing the best output on the BDP-pi is the coax? On the full sized BDPs, AES has typically bettered coax and USB performance (until a BDP-3 + BDA-3 USB stack at least...as some like James claim). You could try a coax from BDP-pi against the coax from the full sized BDPs for a straight up comparison. However, AES is what's recommended by most users and James/Bryston (as noted in BDP(x) manuals) based on listening.
Regarding best playback method, it's what James cleverly said: MPD with internal drive (spinning over SSD).
That option is probably the cleanest and the least 'expensive' option overall when it comes to CPU and resource consumption. Again, this is only my speculation.
Regarding MPD vs. Roon, this is what Roon's CTO had to say about the BDP-1: https://community.roonlabs.com/t/huge-number-of-lost-pcm-samples-in-network-endpoint-output-alsa-software-device/13182/15
RAAT and MPD are really very different systems. One is a media player. The other is audio distribution infrastructure designed to produce interoperability across dozens of manufacturers + DIYers with the absolute minimum of required firmware updates in the wild.
RAAT uses a dynamically defined network protocol. This means that we can fix bugs and make improvements to code running on RAAT devices without waiting for each company to release firmware updates, and without forcing users to go through manual update processes. Dynamically defined network protocols present a different workload than inflexible “baked-in” protocols, and also a different workload than decoding media (which often benefits greatly from CPU features like MMX/SSE).
Exactly how each kind of thing plays out on each device varies based on too many factors.
The BDP-1, in particular, is somewhat unique among Roon Ready devices: it uses a rather primitive embedded x86 CPU 10. It is cache poor, and fairly archaic in its approaches to branch prediction, out-of-order execution, etc. It does have MMX, though. This combination of tradeoffs would make a workload like RAAT (primarily protocol unpacking, interpreting dynamic network protocol, packet reassembly) more challenging for that CPU than a workload like FLAC->ALSA (MMX and memcpy).
Overall, I don’t put huge stock in this sort of comparison. Assuming Bryston has done their job well, and I believe that they have, modest differences in CPU usage should not be allowed to impact the sound quality. There is a lot of “it depends” in constructing a test and measuring this sort of thing. I brought up “differences” in CPU usage patterns to draw attention to the fact that RAAT and MPD take extremely different approaches to audio playback, not to suggest a mechanism of causation for a particular anecdotal report.
This is a good overview of the design goals of RAAT. 21. It might be a little bit surprising how much non-audio-related stuff is required to make a protocol like this successful. Getting audio playback right is just table stakes.
MPD probably creates less noise than Roon within the BDP device itself. MPD can be done via network NAS, USB ports, or internal SATA. The internal option should involve the least processing and thus the least noise, followed by USB, and then network. That's how I've put it together in my head based on comments from different manufacturers including Bryston.
All this so far has to do with noise created by the device itself. The goal is to minimize it. There can also be noise from external USB and internal sources such as hard drives or SSD. In the past I've done comparisons with portable USB hard drives and flash drives and did note differences which I've posted on this forum. I've not tried full sized SSDs with the BDP. I'm not sure how all these compare electrically to each other. Chris has hinted at the billions of transistors of SSD previously. James on two occasions has recommended mounting a rotary drive internally. I'm not sure if that was geared from a sonic and/or value standpoint. The 2.5" 5400 RPM portable WD drives I have are inaudible from 2 feet away in a silent room. With music playing at low levels, they become completely inaudible from any distance. You have to touch the chassis to confirm whether they are spinning or not. Thus, they behave like SSDs as far as acoustic noise levels are concerned. Only their electrical properties remain of importance, along with transfer speeds.
Additionally, I'd have liked to known where the level of noise from these various external sources compares with the noise generated from internal processes such as RAAT or MPD, and if there is a hierarchy of what's the most important when it comes to SQ. You'd need Bryston's measurements or your own measuring gear to empirically answer this. Or you could use your own ears. With me, I can typically pick up the differences and do it consistently, but can find it tricky to answer "what's best?" Everyone's internal audiophile barometer differs as to what's best or if A vs. B sounds better.
OK I'll bite.
At home and at shows I use MPD with an internal rotary USB drive.