Hi Bob,
I am also experiencing slow track transitions using the Id as a rendering device. I just put together my Id last week: bought the USB kit and installed it on a NUC5CPYH with 4GB RAM and a 64GB Kingston SSD. I believe that makes my setup very similar to the Id package from JRiver. I have connected the optical output of the Id to an audio receiver with a 96kHz 24 bit DAC. I spent some time this weekend collecting this information.
A little background on how I use MC. I am running MC21 in MC Server mode on an old Microsoft WHS Home Server. It uses a library of music on the same server, and I have been playing from the Server library on different client setups over the past couple years. Most of my library is ripped ALAC 44 kHz/16 bit lossless files, with a handful of recently purchased HD Tracks hi-res albums, all of which are 96 kHz/24 bit, except one which is 192 kHz/24 bit. For the audio receiver I have relied on Apple Airplay to stream to the receiver. The main reason for purchasing the Id was to be able to play the newer hi-res files on the audio receiver, using JRemote as the controller.
Client 1: Windows 10 machine running MC21 using server library described above over a Gigabit wired connection. The performance on this machine is excellent. Specifically when transitioning tracks randomly or next track etc, using JRemote, the response is so immediate that I cannot tell based on response, whether I am playing 44/16 files, 96/24 files or 192/24 files.
Client 2: Windows 7 machine running MC20 using server library described above over a wireless N connection. The performance on this machine is still very good. No streaming issues and with JRemote, while there is perhaps some small delays when transitioning tracks, it would still be challenging to identify the different resolution tracks based on delay.
Audio Receiver with Id. When playing 44/16 audio tracks, there is a 2-3 second delay in transitioning tracks. I measure this delay after the current track has stopped playing until hearing the start of the transitioned track. I discovered that as I play higher resolution (bigger) files, the delay increases accordingly. So, for the 96/24 tracks the delay time is approx. 10 s, and for the 192/24 tracks, approximately 15 s. I set this Id up as a wireless client, and my first thought was that the wireless connection was the limiting factor. So, I connected the same setup to a Gbit LAN connection, only to discover that the track transition delays were still slow. Then I tried connecting a monitor and keyboard to the Id and tried controlling directly from MC. Same results - slow transition times.
I should point out that the measurements I am observing above are with the spectrum analyzer on the Id MC turned off. When I first noticed the slow times I checked on the forums and found the discussion here. So I turned off the analyzer and then started measuring - so for me turning it off had no or little effect. I also was concerned that I was running mc21 on the server, and 20 on the Id, but my Client 2 seems to work fine with this same version configuration.
Finally, one odd thing I did notice is that the stated bit rate and file format at the top banner of the Id MC doesn't make sense. Even though I was streaming the files mentioned above, and even though JRemote indicated the proper bit rates etc, the Id MC banner was showing 320 kbs and MP3 format. I believe this was true whether I was viewing with a monitor connected or by connecting remotely to the Id and running in GUI mode. In all other ways the sound/experience on the Id is quite good. Obviously though with 10-15 s delays, it becomes challenging to try different tracks.
-Ralph