Does the Nucleus offer anything in terms of sonic improvement over say using an iMac

The Roon company has never advertised Nucleus as a way to improve SQ.

People buy Nucleus for it’s appliance-like demeanor, ease of use and ease of upkeep.


Have they not , I was of the option they have. That the premium price was for everything you said + improved SQ by not having a noisy computer in the chain

They have never advertised an SQ improvement. Please share any links that dispute this.

If by noise you mean sonic noise, then that can be easily addressed by moving the computer out of your listening room.

If by noise you mean electrical, then the Nucleus is just another computer with a computer power supply.

Some people will swear they hear an improved SQ, but some people are suggestible.

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My Roon Nucleus+ definitely sounds better than the fanless QNAP NAS it replaced (which sounded better with all non-Roon-essential apps stopped or disabled, and also sounded better than a Naim Core). Adding a good LPS (in my case a Sean Jacobs DC3 with Mundorf capacitors) improved SQ still further.

Except that it has only Roon-essential processes running and a processor chosen not just for raw power but also low electrical noise.

The Nucleus has fewer processes running because it is a ‘lightweight’ Linux based operating system. It’s a lightweight operating system with fewer code in order to lessen the impact any software updates might have on Roon.

Who told you that fewer running processes result in less electrical noise?
I’ll read thru any source document you care to supply.

Processors are not spec’d based on their electrical noise, low or otherwise…
Again, I’ll read any document that speaks of some processors having lower electrical noise.

There are a couple of interesting posts from Danny about the noise of some of the higher spec processors, while reducing what was running certainly made a difference to the SQ from my NAS.

As for the impact of power supplies on digital equipment, try and experiment if you can: you’ll be surprised. I certainly was. Very…

I seriously doubt that the number of running processes is significantly smaller. I know exactly how many processes are running on my Roon Core machine (Ubuntu 19.10). Anybody care to tell me how many running processes there are on their Nucleus? (I thought not.)

In any case, the more relevant statistic is not how many running processes there are, but how many running threads. Roon is pretty heavily multi-threaded.

Even more relevant is total CPU usage. Which is totally dominated by Roon. The OS overhead, in terms of CPU usage is completely negligible (shows up as 0.0%).

Another ridiculous audiophile myth which has absolutely no basis in reality.

Just so we’re not just talking crap, here’s the actual CPU usage on my Roon Core machine.

“netdata” is the program capturing all the nifty real-time usage statistics. A true audiophile would never run such an abomination while listening to music, as it surely creates a horrid amount of electrical noise pollution.

Aside from “netdata”, everything else (“systemd”, “avahi”, “postfix” and “root”) on the system each register as 0.0% which is to say that they total less than 1/20 of 1% of the total CPU capacity (=400%). Roon’s CPU usage is more than 37 times greater than everything else combined.

I can’t find them. Please post a link. Thanks.

I’m sorry, I just don’t have the time to look in detail. I’ve given it a quarter of an hour. Maybe look for his posts on i5, i7 it could have been in an is faster always better discussion. I did quickly find this, though, on processes and components:

Actively running processes besides Roon stuff? It’s about 5. smbd, networking stuff, ntpd. Ubuntu is a pig in comparison.

All of Roon OS is less 50 megabytes… (not gigabytes … megabytes) – it’s ridiculously slim.


No kernel processes? What a miracle!

(More seriously: that was not an answer to the question.)

A clever switch from “running processes” to “space occupied on disk.” Now you’re going to tell me that the space the OS occupies on disk affects the SQ?

I’m telling you nothing affects SQ – We do not advertise Roon OS affects SQ nor have we ever made such a claim. Roon OS is all about the UX. Size does matter when doing an update, which is part of the user experience.

As for “process count”, you seem to be a guy in the know, and should know this does not actually matter – what matters is context switches. If you really need me to list userland processes:

busybox init
a network manager process (think ifplugd + dhcp + zeroconf + staticip + filesystem watcher)
smbd (samba)
nmbd (netbios)
mdnsd (bonjour)
acpid (idle until you hit power button)
a process to display status on console and watchdog everything

as for kernel, the kernel has been trimmed significantly from what a general OS like ubuntu has… we ship with a small number of modules (thus the limits of device support), and very few subsystems are enabled. Yes, I understand if stuff isn’t used, it isn’t used…but its amazing how much crap is used just because it’s there.

There is no typical Linux distribution server stuff:

cron + friends
systemd + the assload that it comes with
md/lv/pv stuff
snap stuff
policy kit stuff
lxc stuff
log management
email stuff

If you think your ubuntu is lightweight, you can keep thinking so… but you and I have a very different definition of lightweight. Ubuntu isn’t the fat pig that MacOS and Windows are, but even a minimal Ubuntu is in a different class than Roon OS.

as for 0% CPU, stop looking at your gui tool… instead look at /proc/[pid]/status

additionally we build everything minimally as we can – so while your systemd is spewing to the journals/logs/syslog, Roon OS processes are not.

just check this out:

# cat /proc/1/status | grep ctxt
voluntary_ctxt_switches:	1343
nonvoluntary_ctxt_switches:	144
# uptime
 17:20:13 up 97 days, 15:55,  load average: 0.00, 0.02, 0.00

I’m with you on the SQ point here… but you asked a question about the trimness of Nucleus (Roon OS) and I’m responding to that fact.

There are other things that are awesome about Roon OS – such as the fact that multiple versions of the OS can be installed at the same time (super awesome when it comes to updates), everything running out of RAM so little OS-induced SSD wear, full-reset on reboot, and many more things that make it the best “appliance” we could.


@Mike_B, @Sean_Flynn

‘Nuff said.

You don’t have the time and I no longer have the interest.

No matter what, enjoy your musIc.

I stand by my original statement:

Roon’s CPU usage is more than 37 times greater than everything else combined .

And that’s without any DSP. Turning on DSP makes the OS overhead even more negligible.

You have me beat on context switches. netdata does realtime monitoring of system statistics multiple times/second. Nothing a true audiophile would consider running.

Great! We’re all agreed. RoonOS is a fine appliance OS.

I was objecting to the assertion that OS overhead in a generic Linux setup (e.g. Ubuntu server) could possibly make a difference in SQ.

Yeah. I can imagine Roon not wanting to get drawn into any such discussions. They are always fruitless and often offensive. I thought you were genuinely interested, otherwise I wouldn’t have wasted my time on you.

Just use your ears

You have your own idiosyncratic way of interpreting what @danny said.

Now, I’m done wasting my time with you.

That’s what the guy selling rocks says, too. The difference here is that the guy (@danny) selling the Nucleus is telling you in no uncertain terms that, no, it does not improve the SQ.

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Ok so are we all still friends :joy::joy:, I think I opened a can of worms here with the old SQ question, what can I say I’m a noob!!! It’s more or les 50/50 it does and it doesn’t but the guy who sell the Nucleus @danny that’s a bit of a curve ball and I’d be inclined to go with him, normally manufacturers are the opposite saying you can hear God in their products. Anyways thanks everyone for the input and remember keep on rocking in the free word :+1: