DSD Upsampling In Roon DSP - Opinions?

[wklie (Peter Lie)]

If it works for you, you may keep it enabled.

It overloads other people’s setup.

Convolution + DSD overloading powerful CPU

Your situation is caused by processing DSD source material through a large convolution filter generated at a low sampling rate. In this situation, Roon is forced to upsample the filter by a large multiplier, creating an absolutely massive load on the convolution engine. A long filter generated at low PCM sampling rates is not a good match for the “Native DSD Processing” option, and would struggle on any CPU. You are in this situation because you started with REW, and REW is incapable generating…

[wizardofoz (Mr Fix It aka The Wiz)]

after the processing speed drops below 1.4X you will start to get stuttering and at some point could just stop playing.

[Dave_Richardson]

I’m not doing any upsampling at all. As I said in my previous post, the problem is only with NATIVE DSD files.

[Dave_Richardson]

If I remember correctly, you are playing files Upsampled to DSD, not Native DSD files. For me, the former plays fine, the latter does not.

[jussi_laako (Jussi Laako (Signalyst))]

@Koffi

Try HQPlayer and youre not surprised that i99999 in 2028 will not handle all the filters

But GPU offload can help a lot on many things, including convolution…

[Dave_Richardson]

@wklie

No, disabling Native DSD Processing is not implying an output as PCM (which is dependent on other settings as well - you can still force the output to become DSD again). It’s about how the DSP works internally for DSD music.

Peter, you have way more technical knowledge than I do but there is a reason for my confusion. The only difference between these two screen captures is Enable Native DSD or not.

One thing I just noticed is that the Native DSD is using convolution filters with 2.2 Million Taps and the setting for Non Native DSD is using 275 Thousand Taps. I have no idea why, I didn't change any other settings.

[wklie (Peter Lie)]

The reason why is, I believe, explained in danny’s post I linked to above.

If you really like DSD, you can convert the intermediate PCM back to DSD for the final output.

[Dave_Richardson]

Thanks for your help.

[Etienne_Lessard1 (Etienne Lessard)]

Native DSD is also working for me. Maybe the convolution filters generated by Home Audio Fidelity are more cpu friendly ??

[Dave_Richardson]

Thierry @ HAF made my filters.

[Etienne_Lessard1 (Etienne Lessard)]

Sorry. I was just trying to find a potential explanation…

[wklie (Peter Lie)]

Your i5-7500 CPU single thread rating is 2280, more than 12% faster than @Dave_Richardson i7-4578U CPU with a single thread rating of 2031. The CPU single thread performance is the most important factor to determine Roon DSP performance.

Dave’s signal path also contains additional entries of Volume Levelling and most importantly Parametric EQ. So he’s doing far more DSP on a slower CPU.

To further explain the taps, based on my understanding of danny’s post I think it’s like this:

DSD64 2822400Hz / PCM 352800Hz = 8
So the 275k taps for 352.8kHz (after conversion to PCM) is forced to multiply by 8 = 2198k taps (rounding error) when Roon is forced not to decimate the DSD when Native DSD Processing is enabled.

(By the way, HAF is much more popular than I previously assumed.)

[Etienne_Lessard1 (Etienne Lessard)]

Thank you very much for the detailed explanation.