Hello everyone and I wish all of you a Merry Christmas. I am a newbie with Roon and attempting to try out all of the features. I have ventured into Sample Rate Conversion. I am having an issue with what I believe to be clipping and drop out of the audio.
I am running a new Dell Alienware x16 R2 gaming laptop as my Roon server (i9 Ultra 185H, 32 GB high speed ram, 1 TB SSD, Wifi 7 capable running on a TP-Link Deco BE85 Wifi 7 mesh network with a 1 Gbps ISP service), and using a Roon Ready Cambridge CXN100 as my endpoint device. The CXN is natively capable of up to DSD512. I have the “Roon Ready DSD Mode” within the CXN100 settings set to “Use DoP for digital output”.
Here is a screenshot of my Sample Rate Conversion configuration:
In the Signal Path I am seeing 0.8-1.2x processing speed. I am certain that is too low and hence the clipping/drop out.
I should have plenty of CPU muscle with my Roon Server laptop to handle most anything I throw at it, with 16 cores and 22 threads and a max CPU clock frequency of 5GHz+. I am not doing gaming or running multiple applications while running Roon. To maximize CPU processing power while running Roon Sample Rate Conversion I have set my laptop to run in “Performance” gaming mode to increase the CPU performance.
Here is a screenshot of each of the loading of each of the cores of my processor while running the Sample Rate Conversion in Roon and playing a track.
There are only about 3 cores actually running and the operating system has “parked” all of the other cores because they are not needed. Total CPU utilization is also low.
In order to alleviate the clipping and drop out on the Roon side, I have added Headroom and dropped the sample rate down to DSD256. The Headroom didn’t do much for the problem (set at -3dB) but when I dropped the sample rate to DSD256 everything stabilizes and the processing speed goes to 2x. I tried changing/turning off other settings in the Sample Rate Conversion, such as SDM (dropped to 5th order), Parallelize Sigma-Delta moderator (toggled Off), Enable native DSD processing (toggled Off), etc. but the only thing that seems to remedy the problem is dropping down to DSD256 sample rate. I don’t really think I hear a perceptible difference between DSD256 and DSD512 sampling rates but I haven’t been able to run at DSD512 for any length of time to really discern any difference.
I would really like to run at DSD512 just to max out the potential benefits of Sample Rate Conversion (especially since my CXN100 is built to handle DSD512). Has anyone else had this similar issue at DSD512 and no issue at DSD256? Any suggestions on what else I can do to stabilize my system and keep it from clipping/drop outs at DSD512?
Sorry for the long diatribe but I wanted to give a complete description of my issue. Thank you in advance for any suggestions/ideas.
If you using DoP then you can’t go higher than 256 as the dac in the device isn’t capable of pcm rates high enough to support that.
Do you not have option to send native DSD if your not using an external dac to it. Turn off DoP I don’t think you need that for direct playback on the devices dac, only for ongoing dac that may not support Nativd DSD.
If not then the only way to get DSD512 is via a usb input to it and not network via Roon.
Also using wireless for the server will have a real detriment to Roons ability to push DSD in realtime to the device. Your server needs to be wired or the latency will add to the overheads of processing. Also your single core speed is pretty low, Roon doesn’t really utilise more than two cores for a DSP process so having all those won’t make any difference. I would just not bother with upsampling you will get little gain on a streamer like this over just letting it do the work internally.
You also want to give headroom for any DSP
Processes to avoid clipping.
The setting for DoP seems to be in the Cambridge Audio and not the setting in Roon how to handle DSD (otherwise you can’t select DSD512 in Roon for upsampling).
Your CPU should be able to handle such an upsampling (I do it also with an i9-11900).
But it seems, that in your laptop the turbo modus is not enabled btw. blocked. My CPUs are running until 5GHz while upsampling multichannel to DSD256 (needs much more horse power than upsampling stereo to DSD512).
So check your laptop settings for power saving or silence working.
Then: Don’t use Wifi for your Roon core, how CrystalGipsy already mentioned.
Thank you very much for your reply. Upon further research into exactly what the DSD setting in my CXN100 is doing I now am not certain what it is doing. It has two choices, Use DoP for digital output (current setting) and Use PCM for digital output. When I set it to PCM for digital output it obviously converts to PCM. There is a preface note within the setting that says “Due to limitations of SPDIF, DSD rates above 64x are only available on analog outputs. If you want to play DSD rates above 64x on digital outputs, you need to change the Max Sample Rate (DSD) setting in the Roon app to 64x.” So it seems maybe that setting in the CXN is pertaining to the use of a digital output on the CXN, which I am not. I am using balanced analog. I have a request in to Cambridge Tech Support to explain to me how to use the DSD capabilities of the CXN with Roon DSD512. And you are perhaps correct in saying I may be better off turning off DSP in Roon and let the player do its thing.
With regard to WiFi versus Ethernet my PC is a WiFi only PC. I have no Ethernet port. I haven’t had any internet connectivity or bandwidth issues thus far but it is something I will keep any eye on.
For Roon the single core speed is more important that the numbers of cores. Your are correct that the Processing Speed of 0.8 on a single core is too low for the other processing Roon needs to do. Dropouts and skipping occurs when my processing speed is dragged down to 1x.
The Ethernet port on my MSI gaming Laptop quit working so I got a USB-C to Ethernet adapter. You could try that. For me the speed test when from 400 with wi-fi to over 900 with Ethernet using the adapter.
With my Roon Ready dac connected to NUC/ROCK over Ethernet it plays dsd 512 stereo and dsd 256 8 channel with no processing speed displayed. The processing speed is only shown in the signal path when it is below 100x. This is DSD files to DSD player with no DSP conversions.
Keep it simple to start with, Ethernet for Roon Server to Router with network to Roon Ready Cambridge CXN100, then see what you can pile on the processor from there.
You need to look at each core not overall utilization.There are some things, like sample rate conversion, which only run on a single core per channel so if you run out of horsepower on the core the others cannot help. As @Mike_LC noted, this is why single core speed is more important for Roon.
You may also look at the thermals and especially with trying to use a laptop. If one core is getting you > 1x speed but then is throttled because of thermals you’ll drop below 1x and get a drop out (not clipping, I’ll get to that). Sounds like you’re really close but 512 may be possible on that laptop without some tuning.
As far as clipping… in digital audio amplitude, or volume, is on a finite scale. Clipping happens when you go over a max. Clipping in analog is distortion, somewhat pleasant depending on the circuit. In digital this distortion is noise. In any sample rate conversion you run the risk of exceeding the maximum which is why its recommended you add headroom management (start with -3 and turn on clipping indicator). More on headroom and clipping here https://help.roonlabs.com/portal/en/kb/articles/dsp-engine-headroom-management
If you don’t see the red dot you’re not clipping. Clipping will not cause silence in fact you may not even notice it depending on the source material but, a gap in playback a dropout. The DAC had nothing to play because Roon couldn’t keep-up to process that sample so it “dropped” the sample and you heard a dropout or silence.
Converting from PCM to DSD is not trivial and DSD512 is 512 CD sampling frequency (44.1khz x 512 = 22.5792Mhz. That does not mean DSD512 is 512 times better than CD because you can’t directly compare DSD and PCM.
Anyway, i got off topic. Check thermals, look for ways to stop those cores from throttling, and you might be able to get there. Otherwise enjoy DSD256… or use higher PCM rates and see how you like those. PCM to PCM is a lot easier on the CPU.
oh, yeah, and I second ditching the wifi. Roon Server / Core wants a wire. Loves a wire. Lots of problems go away with a simple wire.
Turn them both off you don’t need that setting on at all. No need to wait for Cambridge Audio it’s only for connected dac which you are not using. Stil you will likely still struggle upsampling to DSD512 for little gains. It’s not a light process and really not needed in your case but try is you must.
All pcs are capable to use Ethernet you just need a usb to ethernet adaptor to do it that’s all on some models. Wireless isn’t suited for server related tasks and then you have high bandwidth data like DSD less so.
Thank all of you for your very informative comments and suggestions. I am not an expert so this is all very helpful. Some responses to your feedback:
I had already looked into a wifi adaptor. Based on the consensus opinion of commenters it appears I should never run Roon Server on a wifi connection. I will install a wifi adaptor and use wired ethernet. It appears more and more laptop manufacturers are going to “slimline” form factors for laptop equipment and this means RJ45 connections are disappearing.
My PC is brand new and I am still learning the ins and outs of tuning it. It is a gaming laptop but I am not a gamer. I tend to want the highest horsepower of everything, not that I need it but I want it. So that is why I bought the one I have. I have switched to the highest performance mode (Overdrive, which clocks the CPU and GPU at a higher speed) and didn’t see any real improvement on the processing speed in the Signal Path. I will continue to play around with that. But I don’t see evidence of where throttling is occurring due to thermals. I will continue to monitor.
I did turn on the clipping indicator in Roon but never saw a red indicator in the Signal Path indicating clipping was occurring. So I surmised it was drop out. This is likely confirmed by the fact the audio was completely dropping out and then Roon would go to the next song without finishing the current song. So after this event occurred Roon was giving up or losing its place on the current song and said “the heck with that, I’m going to the next song.”
Roon is a heavy network user, I’ve seen and used the term Network Beast. It seems appropriate. So having the Roon server on Ethernet frees up the Wi-Fi for endpoints and everything else.
When I first started using Roon it was running on my desktop over Wi-Fi about 40’ from the router. My home built in the 60’s did not have Ethernet.
Roon server had to communicate with the router to query the internet connection, then back to the server, then back to the router, then out to the endpoints. It worked but I did experience dropouts, and usually when I was showing it off to visitors. I had my home wired for Ethernet (8 locations - $3500.00) and that eliminated the dropouts. The only dropouts now are when the processing speed gets dragged down to 1x for DSD 256 5.1 conversions to PCM.
To further the analogy, you bought a V8 with peak torque at 2000 rpm, while Roon actually would run better on a four cylinder with peak torque at 3500 rpm.
Mr. AJ, I disagree with your comment that I bought the wrong tool. I bought the laptop not for a host for Roon Server, but for other functionality it offers. I am trying out Roon on it and, once I have thoroughly mastered the basics I intend to purchase a NAS or a mini PC to host Roon Server. Only then will I know the exact requirements for the purpose required. Thank you.
Menzies, I really appreciate your courteous reply. I’m sure AJ means well.
I really like Roon thus far, especially RAAT. Being able to cast bit perfect audio resolution is much better than AirPlay or Google Play. I really appreciate the counsel from the commenters to my original post. Very helpful and I am following their advice. Have a great day!
