Nucleus vs Nucleus+ DSP

On a reseller website it states for Nucleus:

  • Limited DSP (EQ, headphone crossfeed, etc)

For Nucleus+ it states:

  • Extensive DSP (upsampling, convolution, etc.)

Does this mean that the Nucleus will not be capable of doing this or that it will be but depending on the number of clients and load it will (or not)?

All DSP features work fine on my 9 year old i7 (1,73GHz) laptop. I want to buy the Nucleus as I don’t think I need the + power but want to be assured that I can use DSP.

As I understand it, the Nucleus has an Intel Core i3 CPU, while the Nucleus+ has a Core i7. That would explain the difference. Core i3 being more limited than i7. You can use DSP on an i3, but only to a limited extent, as stated on the reseller website.


A current i3 7100U@2,4GHz has a CPUbenchmark of 3784. My i7 Q820 @1,73GHz has a CPU benchmark of 3252 and can do all DSP currently in Roon. Why would the Nucleus i3 based version not be able to do e.g. upsampling?

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try a convolution filter + DSD512 upsample – it will fail.

Ok maybe I shouldn’t have used the word ‘all’. A convolution filter is not the most used filter. My question was about upsampling. @Danny; you as COO should be able to answer the question better then proving the point that a i7 Q820 cannot do all…

I think we are having a misunderstanding. I thought my example was a concise demonstration that answered the question at hand. Clearly, I failed. Let me try again.

The question asked was:

There are cases in which the i3 may or may not work. It depends on what you are doing and how many zones you are doing it in. Upsampling to DSD512 is one of those cases, adding convolution filters for room-correction purposes (which is quite common) is another, especially when tied to upsampling.

Additionally, I know the 6th generation NUC6i3 was found to have trouble upsampling a multichannel stream to DSD256 for a partner’s multichannel server/DAC combo.

I specifically used the example of upsampling and convolution since your original post pasted those 2 points as the definition of “Extensive DSP”.

The premise of your question is that “if X can do everything, why can’t something better than X”. If you reread your comment knowing that the i7 Q820 cannot do everything (the point of my demonstration), then there is a good chance that the Nucleus would also not be able to do everything, as it is only incrementally better.

If you are happy with the first generation mobile i7 Q820 @1,73GHz, you will probably be happy on the Nucleus. However, consider that while the Nucleus has a faster more modern CPU, your existing i7 has twice the number of cores, so a better evaluation could not be done unless we know your use case. How many zones, what types of DSP?

A “CPUbenchmark” result only paints part of the picture. It is why benchmarks, in general, can be useful tools, but should not be used to make decisions about non-benchmark use cases. When reviewing a CPU, you will find that every reviewer will use multiple distinct benchmarking systems, all coming back with different answers. I personally am not familiar with that specific benchmark so I can’t use it to make any decisions.

Our advice, in general, is that the Nucleus is fine for most people, but if you want flexibility, a growth option for most things in the future, the Nucleus+ is better. Large libraries, a large number of zones, heavy DSP usage, etc… they all could use Nucleus+. That said, the Nucleus is no slouch.

While the above does not directly answer your question, I hope it helps answer the spirit of it.


Danny,we probably were but thank you for your clear answer. Indeed a single CPU index doesn’t say all about a CPU as it is depending on the load type placed on it. I am at the point of purchasing the Nucleus and was triggered by the statement that upsampling is only listed for the + version and started wondering whether a feature like that was either disabled in the non plus version or that it is available but depending indeed on number of zones etc.

I now understand that all features are available but you have to account for a performance limit.

As for my use case; I will be using advanced features only in the main zone (listening room). I may play around with upsampling and EQ. I have 4 squeezeboxes in 4 different rooms so that would mean 5 zones in total. The number of concurrent used zones I’m pretty sure will never go above 3 and and synchronization of music is something that will not be used (never had a reason to do so for it with the Squeezeboxes).

I do not know if I am in a real demand for room correction. I’m curious about the effect but don’t expect it to be huge considering room acoustics and acoustic treatment already performed but then again the audiophile virus on continuous improvement is non-curable (I must admit after too many upgrades).

Given this I suppose the Nucleus will do for my use case (without the room correction).

Thanks for the thorough answer


I am in need of a nucleus. To be honest the only reason I want it is to access the crestron module for control. If that were available for DIY Rock I would much prefer that.

Having said that I want room correction DSP for 13 zones. Will I need the nucleus + to handle that amount of dsp or is even the plus going to struggle with 13 zones ?

What kind / type of DSP will you be using?

13 zones but one at a time, ot 13 zones at the same time?

If you are playing one at a time, the existence of the other 12 does not matter.

Good point for clarification. I want the ability to play all at the same time with room correction dsp on at 10 zones

That is some serious load.
Because even if you are playing the same music, Roon’s processing is separate for each zone because both device characteristics and room correction may be different.
(And if you are playing 13 different streams of music — jeez, man!)

So you need to be careful of the choice, and get dome serious advice.

That said, I don’t want to sound pessimistic: when I play 24/96k music with a 131k convolution filter, my Nucleus shows a processing speed of 22X, and 19K with 24/192k music (and it’s a regular Nucleus, not a Nucleus +). So I have plenty of capacity, even for 10 zones.


Good to hear your experience. I suspect I’ll end up coughing up for the nucleus +

Hello; my intention is to run Nucleus as stereo only. In which case - will the simpler model offer inferior sound quality ?
Best rgds. Ola

Both Nuclei will sound the same.

Things to consider are library size (# of tracks), number of zones that will be used simultaneously and projected use of DSP (DSD upsampling is ‘heavy’, more so when combined with Convolution).

In short: with <100K tracks, a handful of zones and no DSP upsampling, you’ll be fine with the non-plus Nucleus.

ihe Roon Nucleus music server with Intel® Core ™ i3 with 4GB RAM can upsample all DSD variants. If not, which formats can the i3?

use only one zone, no room correction and only 1 client

Freundlichen Gruß

Detlef Franke

I suspect the i3 cannot keep up with upsampling to DSD512. I say this based on my Roon server, which has a Zeon E3-1270v6, which is roughly equivalent to an i7-7700 but with ECC memory. Upsampling to DSD512 consumes an entire core, and that’s without any room correction. Enabling multi-core upsampling brings the Roon performance metric up from ~1.1 to ~3.5, which still is still heavily stressing the system. When I tried DSD256 single-core, it still consumed the better part of a single code (Roon metric of ~2.0 if I recall correctly). So I would guess that upsampling to DSD256 may also be a stretch on an i3. I would expect DSD128 to be doable on the i3, though.

Upsampling to very high levels of PCM is also fairly taxing in my observation. Not to the extent that the high rate DSD consumes, but PCM768 is still easily half a core on my system.

My NUC6i5 upsampled to DSD512 at 1.4x (multicore processing). Even though I was not particularly enamoured by the outcome, it never skipped a beat.

An i3 is probably pushing it.

When I played with upsampling I got dsd128 T 4x speed out of my 4th gen i3 dual core it never dropped a beat and about 20x for 384 pcm. My systems don’t go higher than this so no idea of it can or not. So a newer one should in theory top this. I could do two zones in tandem doing this

Hallo Detlef
der Nukleus behershct auch DSD 512! Gerade wenn keine weiteren DSP Funktionen aktiv sind. Roon zeigt bei der Wiedergabe oberhalb des Titels einen gelben oder grünen Punkt, bzw. einen blauen Stern. Wenn Du darauf klickst öffnet sich ein Kontxtmenü. In diesem, je nach Einstellung, wird die Leistungsanforderung an den Nukleus angezeigt.
Aber, no Problem, alle Formate funktionieren.
Solltest Du weitere Fragen haben, ich bin vom Deutschen Nukleus by Roon Vertrieb: