I am sorry that you have problem to play SACD ISO using Audirvana.
I am playing them on old PC with Audirvana 3.5
For now I gave up to use Audirvana Studio to play any files.
I bought discounted 1 year subscription and I had problems to play DSD 128 file which is kind of big obviously. Also Radios vanished, only very few stations left being displayed in AS
AS I installed on Mac Mini and I don’t know what is happening now in Windows using Audirvana Studio.
I tried AS in windows for a month when just came out.
I do not what is happening with current version.
On Mac I have installed version 1.6.1 and it is not stable so I am back on Old PC with ver 3.5 which I bought just few days before its termination date in May I believe.
So I can speak only for 3.5.46 version behavior on Windows 10 Pro 21H1
My old pc built
Motherboard: Asus P5K
CPU Intel Q 6600
8 GB DDR 2 1066
Windows installed on 256 GB Kingston SSD
Audirvana library stored on 10 TB WD Elements external HD connected via USB 3 Vantec PCI express card mounted in PCI Express slot on motherboard.
Yesterday I was playing few different SACD ISO albums for testing purposes to different Chromecast Audio dongles and to Google Nest Mini 2 speakers configured in google home app as stereo pair.
I don’t have any idea how Bubble UPNP app is converting this files coming out of Audirvana in order to be streamed to Chromecast points.
I suspect that probably isn’t very high spec.
But it is important for me that I can play those files when I am falling asleep to Google Nest Mini and to garage when I am working there. At that point Sound Quality isn’t that important to me.
I noticed that my set up is not playing those SACD ISO immediately.
It takes some time to load them.
For streaming 44.1/16 Flac my old PC doesn’t work that hard and that process is much faster.
I guess Most of the chewing preparation for streaming Buble UPNP is doing.
I installed Bubble UPNP and I set my Chromecast END points as DLNA Renderer in Bubble Media Renderers settings.
I hope that this may help.
Normally I don’t have any problems to play SACD ISO in Audirvana 3.5 on this old PC
It takes maybe 15-20 seconds to load and start to play (maybe more time depends on the image)
Once it start to play than it would play whole album non stop no problems.
Streaming to Chromecast it is different story.
It takes more time to load and later between tracks there is long gap ( MEDITATION TIME for Bubble UPNP server)
Now for Audirvana settings I have Ifi Zen Dac connected to PC USB 3 and ASIO original Ifi 3.2 windows driver for that device is set up.
With my set up I have no problems but yours could be completely different and that may change the whole picture to negative experience.
Are you relating your bad SACD ISO play to older Audirvana versions or to new Audirvana Studio ?
My PC is playing SACD ISO using Jriver Media Centre 26 also almost imediately but sound quality isnt that good as in Audirvana.
Audirvana always is loading every file to its buffer in order to perform perfect playback (maybe that time is needed to apply that special tweak for sound quality which I don’t mind as long as I have satisfying sound) SACD ISO is complex so that time is longer. I got use to it with my old gear.
I prefer JRiver interface and easy of use and other aspects but using Jriver and Jriver built inn DLNA server I couldn’t stream to Chromecast.
I used Bubble UPNP and also bad results with Jriver to streem large files to Chromecast.
SACD ISO was completely out of question to be streamed over my home network.
For playing files instantly off course Jriver is better.
Neutron Player $ 10 in Microsoft store is playing SACD ISO almost instantly also on my PC and sound is much better than Jriver. There is one week free trial
Maybe sound quality it is comparable to Audirvana ?
Tried to play same file just now Audirvana vs Neutron on same PC set up.
And winner is Audirvana 3.5 big time !
If you didn’t try I would recommend to install in spare time
It has very strange interface but it is playing anything with ease and it automatically recognized my DAC
Neutron Player it has its own DLNA/UPnP server built inn and it can output to Chromecast most files but no sound when SACD ISO image is loaded .Maybe something has to be changed in settings. Other files is streaming to Chromecast instantly.
It is Superb cheap Player on steroids’ and our Forum Member Doudou told me about it !
I tried Roon few times and it is streaming files including DSD instantly on its own to Chromecast Audio but sound quality is more neutral like in Jriver and not as good as Audirvana .
We know that you have 16 GB of RAM that is way more than enough.
I am wondering what are the remaining components on your pc ?
Your PC must be newer than mine because my motherboard is taking 8GB of RAM max.