RPi4 doesn't have USB/LAN bottleneck

Gone is the single-lane USB bottleneck which hampered performance on older models, and Raspberry Pi 4 shines in benchmarks as a result.

We will see… Just ordered a couple of them

Ethernet is directly connected to the SoC and the USB is via a PCIe bus. Hopefully, that should mean a marked improvement in use cases…

I missed the first run of Pi 4s, but am looking forward to updating my music server to one of these. The new HW design for the Ethernet will make a big difference for NAS servers.

Oops… techcrunch.com/2019/07/09/the-r … -c-cables/

We just released an experimental build, please provide feedback:

experimental-volumio-build-for-raspberry-t12640.html

I use wifi and dont use usb :laughing:

Did anybody test a Pi4 vs a Pi3B+ on both local (USB or SD) and remote (NAS) music source and appreciate audible difference?

Yes!

Mr. Hans Beekhuyzen on his YouTube channel: youtu.be/cjqEPyMr1zI

Regards

I think I stay with 3B+ and wait for RPI 5.
:slight_smile:
That heating RPI 4 and sounding worse convinced me.

have tried the raspberry pi 4b-2gb model with kali reclocker with the allo piano 2.1 on top.
and I have to admit that there is slightly less detail present and less pronounced sound compared to the raspberry p3 b +.

USB I’ll have not tried.

Verstuurd vanaf mijn Nokia 6.1 met Tapatalk

I have run volumio on a rpi 4 for a while now, I have not notice any difference between 3 and 4, use USB to an external DAC. The temperature is below 60C, I have only a passive heatsink on it. I did not have any problems with USB on the 3 either.

I just wanted to give a huge thumbs up for the Raspberry Pi 4 when used with an external USB DAC. :smiley:

All previous models of Pi have issues with dropped packets over the USB ports during isochronous transfers (used by most high end DACs) which manifest as subtle clicks, pops or even obvious dropouts in the audio.

The severity of the problem varies with the load on the CPU, the model of DAC you use, (due to differences in transfer modes) and the sample rate you try to send to the DAC (worse at higher sample rates) but it is always there. See the following for more details:

246-umc204hd-audio-glitches-spotify-sample-rate-t7682.html

I opened a ticket 2 years ago with the Raspberry Pi developers and the problem has been acknowledged and confirmed by many other people but not fixed in that time:

github.com/raspberrypi/linux/issues/2215

I have a Behringer UMC204HD USB DAC and it is almost unusable on the Pi 2 due to these issues. At 44Khz 16 bit there will be the occasional noticeable click but at higher sample rates it can be un-listenable.

Due to this I switched to running Volumio on a Cubox-i which I already had handy - this solved the USB dropouts however I was always stuck running old community builds of Volumio with no easy (in place) upgrade path.

A few days ago I bought a 1GB Pi 4 with the official Raspberry Pi USB-C power supply, and I am over the moon. :mrgreen:

The new USB controller in the Pi 4 does indeed fix this issue 100% and I now have perfect glitch free playback on my USB DAC at all sample rates up to the maximum 192Khz 24 bit. The Volumio web UI is much more snappy than either the Pi 2 or the Cubox-i as well.

Another unexpected and pleasant benefit is that the noise levels on the 5 volt output of the USB sockets on the Pi 4 is extremely low.

On the Pi 2 the 5 volt output powering the USB DAC is so noisy that you can hear CPU “chirping” in the background through the DAC’s analogue output while music is paused, even at normal volume settings and I found connecting the HDMI from the Pi to my TV made the noise much worse again. Very noisy. :imp:

The Cubox-i was quieter but there was still quite audible CPU chirping and background noise passing through the DAC if I turned the amplifier volume up a bit (to 10 oclock) that shouldn’t be there.

I had been considering using a separate linear 5 volt power supply to provide clean power for the DAC separate from the Pi however I thought I would try the Pi 4 as is first.

I was very surprised to find out that there is NO CPU chirping or background noise at all from my DAC when powered from the Pi 4. :open_mouth: :slight_smile: I can turn the amplifier all the way up to 2 o’clock with music paused (well beyond any normal volume setting even for loud playback) until I hear any hiss at all and that is just smooth analogue hiss from the amplifier which is still present when I unplug the DAC. So essentially the DAC output when powered from the Pi 4 and not playing is noise free.

I was not expecting that at all as Pi’s are notorious for noisy USB power. I don’t know whether it’s specifically the official Pi 4 power adaptor that is very good, or whether there is additional filtering on the Pi 4 motherboard for the USB power but whatever it is it is exceptionally clean, at least when that is the only USB device connected.

So if you have or are considering a USB DAC for Volumio (especially one supporting high sample rates) I wholeheartedly recommend the Pi 4 (when used with the official power adaptor) and my advice would be to forget all models of Pi before the 4 as they will invariably have issues with glitches in the audio due to USB performance whether subtle or overt, and it is just not worth it.

The only negative I have to say about the Pi 4 so far is that the CPU does run quite hot - 74C in an closed plastic case or 64C with the case lid off - I am considering getting the aluminium Flirc case because while it’s a bit pricey it’s a very nice looking case, drops the CPU temperature by about 20C (according to reviews) while being silent with no fans, and the fact that it’s metal means it probably provides some shielding at audio frequencies as well.

Im not an format expert but this play glitch free with my USB Khadas Dac and RPI 3B +Brutefir.
60% cpu load over Wifi.
And no noice from USB port with standard RPI 2.5A adapter
Samplerate: 5644800 Hz / PCM Samplerate: 352800 Hz
Channels: 2
Bits per sample: 1
Bitrate: 11290 kbps
Codec: DSD128

Not all USB sound interfaces are affected in the same way - it depends on the “bInterval” parameter advertised by the sound interface - if it advertises a bInterval of 1 you will have problems, with a higher value you may or may not have obvious problems, or may only have problems at very high sample rates.

In any case the USB controller in the Pi 0-3 is very poor and not of a standard suitable for Hi-Res USB audio IMHO. No point getting a high quality DAC (of which most use bInterval 1 for low latency) and then attaching it to a very unreliable USB controller…