Nucleus struggling with DSD512 since buid 571

Using bonded ports on synology could we be causing the issue… try dropping back to one…just to see if it helps

might be time to fully document and update us on the whole setup…as is normal practice for support threads

In order for Roon’s @support team to better assist you, please provide a brief description of your current setup using this link 1 as a guide.

The image needed to be scrolled up to show the speed.

DSD 512 processing speed between 1x and 1.1x. Dropout start when nearing 2minutes
DSD216 processing speed between 2.7x and 3x works flowlessly
Obviously same piece used for comparison from 0 to 2 minutes.

That’s too low. It has to be above 1.3x. The value should be higher if you have enabled Parallelize Sigma Delta Modulator, but since you already have that enabled, we need to find out what causes your CPU to be so busy.

Please make sure you do not have any background analysis ongoing.

How could we explain that going back and forth between DSD 216 and DSD 512 it still shows such difference in processing speed. It would haave background process would run all the time or not but would not start only when under DSD512?

DSD512 upsampling of course uses much more CPU power than DSD256 upsampling, and must result in a lower processing speed. That you have a lower processing speed with DSD512 than DSD256 is absolutely normal and is not a problem at all. I’m not sure I understand your question. That you have a processing speed below 1.3x is a problem.

I would try adding some files to the core machine and add those to your library to test upsampling those to see if the connection from NAS is causing some of the slow speed for processing. Processing speed is a number of factors and not just cpu.

I will do by tomorrow.

Thinking about your question more I figured that it may be confusing if not knowing that the processing speed is relative, not absolute (as in traditional benchmark scores). The definition is:

Processing speed = (duration of audio processed / duration of CPU time it took to do the processing)

A lot of words spent on figuring out that an i3 NUC won’t do DSD512 upsampling reliably… No, it will never do that.
Upgrade to a more powerful core if you wish to upsample audio to DSD512. Some minuscule change in software v571 seem to have pushed your setup over the edge but you will have been very near this edge previously.


I do agree. I wish Roon will bring more clarity in the future to specification limit description spelling out exactly what can or cannot be done.
« Certain combinations of functions using DSD source or destination formats, upsampling, or multichannel processing may not be possible. » such description is simply too weak. Quite expensive for a new bookend. Hopefully NUCLEUS+ « All DSP functions available. » won’t face the same issue too soon.
Last word: that does not take out anything from the fabulous ROON performance as a software.

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The range of DSP functions is such that the Nucleus+ is not capable of all DSP functions under all conditions. The more you ask Roon to do, the more power it needs.


For what it’s worth I’ve been experiencing the same issue. I’m on a Nucleus+, all wired with a 1Gb connection to the internet. AudioQuest cabling everywhere. Upsampling everything to DSD512 comes in around 1-1.3x processing speeds and will sometimes fall behind the playback so it cuts out around the 1-2minute mark just like the OP. Parallelize is on. A few different Signal Paths below. I did expect the Nucleus+ to have no problems with this since i’m just playing in a single zone. Thoughts?

And here are my DSP settings for the signal path above.

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Nucleus+ DSP capability: All DSP functions available. :frowning:
If the Roon OS web interface showed CPU loading and frequency information, it would make it easier to find the fault. But you in this case like many other users of Roon OS have become hostage to the whims of @danny, unwilling to add these functions to the web interface (although it is not difficult for him to do so) :frowning: .

Try turning off headroom adjustment.

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Thanks for the suggestion Peter! Unfortunately I had tried that without success (see screenshot).
My top idea right now is actually blaming the Pro-ject S2 digital. It only handles USB 2.0 - so I actually wonder if the bottleneck is the USB connection to the Pro-ject… but then I looked up the bandwidth requirements of DSD512 they seem well below USB 2.0’s max bitrate so I’m not super confident on this explanation.

My other thought is that maybe the upsampling isn’t being effectively parallelized across all of the processors of the Nucleus+. I note that when I turn of parallelization, the processing speed drops to about half (~0.6x)… so maybe it’s only using 2 of the available cores to upsample vs using all available cores? Anyway I fully admit I have no idea what I’m talking about :slight_smile: Just having fun wondering what’s going on.

The good news is, in my case, even with only 1.1x it’s pretty rare for it to stutter to a stop. I did expect it to not struggle so hard with it being the Nucleus+.

USB 2.0 high speed is 480Mbps. DSD512 is only 22.579MHz, so stereo DSD512 should take 45.148Mbps.

With that turned off, you use only one core to do PCM to DSD upconversion. With that turned on, you use two. So it should always be turned on.

That’s not good enough. I require things to work for a specified level of performance objective. For me, DSD512 upsampling without other DSP (such as headroom adjustment) is the baseline requirement.

There are many Nucleus users here. If the cause is with the Roon update itself I expect to see a lot more complaints. So at this point I suspect there may be something else going on.

There are more folks having issues upsampling also;

It doesn’t seem to be a general problem though, none of my Cores exhibit the samme issue.

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