I've been chewing over my solution for possible improvements but it's pretty minimalist.
The wap is business class with only one rj45 and a single radio, no dchp, routing, switching, or security, and only one vlan. There's not much going on in there. I was wondering whether there might be more silent devices electrically. It's on a linear psu so it comes down to components and layout.
Running a lean operating system and providing clean linear power often provided positive results, your PSU should be doing its job while such an early model of Cisco Small Business Pro turned out to come with the most basic hardware
• 64 MB RAM
• 32 MB flash
In other words, they must keep the software part to a bare minimum or else having 64 MB of RAM wouldn't cut it. And then having the least amount of RAM could be an advantage in terms of noise and current draw etc.
These Ram modules are a custom order type, similar to the Apacer types popular in the Jplay forums, but taking it just a bit further. They do create less noise and draw less current then other offerings.
I didn't have linear power on my router previously. I should do that before trying anything more complicated.
In the past I used a 3rd optimized pc as a windows 2016 nas and before that a qnap on linear power. I discovered Marcin was correct; with Jplay Femto the music sounds better with files resident inside the control/server pc. If only I could afford 8tb of ssd.
As per my signature I already run both pcs in ramdisk. I consider windows server much better sounding than windows 10.
Maybe you could consider giving this a try?
Today for the first time I got satisfying sound from my external 4TB usb drive using wtfplay. Before today I much preferred playing from a little optane disk but it meant I had to copy files over (converting them to wav while at it). Today I placed the usb drive far away, in another room, powered it with 5V linear battery power and connected it with a fibre optic usb 3.0 extension cable:
The NUC -- unlike my previous PC -- recognized the drive!
The SQ was almost indistinguishable from that with optane.
Another step forward...
Other than that, you could do some research on InfiniBand and SMB Direct etc. since the hardware became so affordable already.
CPU offload with RDMA might also be a good idea for accessing SMB shares
What you really want to do is reduce your hardware active processing times as much as possible. The net effect is much like a class A amplifier, you have a higher baseline power consumption, but power draw does not vary much, and this is very good for a more “natural/relaxed” sound. I hope this makes sense 🙂 But you do need a power supply which is very comfortable supplying the load. You really want the least possible variation in load, and higher cpu power / bandwidth systems are better at that with very low load music playback processes.
RDMA network adapters offer this performance capability by operating at a line rate with very low latency thanks to CPU bypass and zero copy (the ability to write directly to the memory of the remote storage node using RPCs). In order to obtain these advantages, all transport protocol processing must be performed in the adapter hardware, completely bypassing the host OS.
This direct transfer operation allows the application to access remote storage at the same performance as local storage.
These NICs implement RDMA in hardware so that they can transfer data between them without involving the host CPU. As a result, SMB Direct is extremely fast with client-to-file server performance almost equaling that of using local storage.
We do see about a 25% CPU offload with RDMA, so this gives a lot of CPU back to the application, not to mention that you can further consolidate the amount of density that you have within that rack.
There's no need for an expensive InfiniBand switch, two PCIe adapters could be connected to each other directly.
ConnectX-2 could be easily found on eBay etc.
Simply get firmware version 2.10.0720 for ConnectX-2 in order to enable RDMA
Custom Firmware for Mellanox OEM Infiniband Cards – RDMA in Windows Server 2012
Still not too much money to lose even if you weren't able to get SMB Direct (a.k.a. RDMA over SMB) working between your Server 2019 machines, and then ConnectX-2 also worked fine with Windows 10 Version 1809 (i.e. equivalent to Server 2019)
Finally you just need to find out what cables are compatible with those PCIe adapters