the audio streaming series

Raspberry Pi 5 - a new audio streaming giant

Since mid of November 2023 I own the recently launched Raspberry Pi5 with 8GB RAM. Not that I was unhappy with the RPi4 based setup. Though after looking at the specs and knowing what higher performance gear can bring to the table, there was no way not to try the new toy. 

Note: Before you run and order the device, you might want to read the whole article. In any case also order a cooling case at the same time! The RPi5 needs cooling!!! 



If you look at the specs you'll see that the RPi5 betters the RPi4 on almost all aspects. Here are my key picks:

  • around twice as fast as the RPi4
  • fast LPDDR4X RAM
  • it comes with 4 PCIe lanes now
  • it allows to attach a M.2 NVME HAT via single PCIe lane
  • 2 x USB3.0 ports that offer simultaneous 5Gbit/s transfers
  • a better motherboard - that's needed to cope with the higher speeds and throughput
  • ( the vastly improved GPU performance won't affect headless audio operations)

What's not really nice:

  • IO port change - ethernet went to the left (DejaVu?)
  • runs at higher temperatures - passive cooling still possible though
  • higher power consumption under load
  • same power consumption @idle - modern devices should run lower!
  • still USB3.0
  • still no Wifi 6
  • Wifi antenna as poor as the RPi4 antenna and still no option to go external
  • due to cooling needs, working with HATs is becoming tricky

The software side:

  • RPiOS Bookworm supports the RPi5 out of the box - status: WIP (work-in-progress) 
  • the firmware is still WIP
  • some features are not available (e.g. LED off) 
  • things got - as expected - a little different and a bit more complicated with this device and RPi OS Bookworm
  • (I am not sure which audio OSes properly support RPi5 already now)

It took me about a month to get my own software setup (OS, rt-kernel, custom apps, optimizations) properly shaped up. And there's still stuff to do. 

Power:

The early announcements were shocking. It seemed none of the old power supplies could be used anymore. In real life things look a bit different - at least for my use-case. With SD-card and a basic boot and clock setup, I see around 750+ mA short term peak during boot. Around 550mA @idle. Which is very close to the RPi4. The community, including me, thinks it should be less for a modern chip. The RPi designers response was something like "give us some time, Rome was not built in a day". OK. That's RPi world. Let see what's gonna happen.

When booting from SSD via USB-Sata cable I had to add around 200mA to the bill.

The power chip seems to limit USB current to 600mA on non-compliant power supplies. You can disable that safety limitation manually in config.txt (I did) if you know how.

I btw attached the RPi5 to me Allo Shanti 3A output. That works rock solid.


Temperature:

@1500MHz idle and the GeeekPi passive cooling case I ran @ around 35 °C. @2300MHz and force_turbo=1  I hit around 54°C @21°C room temperature. 

That's why I am quite happy with the passive cooling for my use-case. I don't want electrical fan-noise mess up my power rails.


RPi 5 as audio streamer

My RPi 5 audio chain setup looks currently like this:

  • RPi5 8GB RAM with GeeekPi case
  • Samsung SSD hooked up to USB3 via SATA-USB adapter
  • Allo Shanti 5V/3A supply
  • iFi USB filters on DAC and SSD
  • IanCananda ShieldPi Pro (GPIO filter and buffer) attached via 90° GPIO adapter
  • Gustard A18 hooked up to USB3
  • my own OS, realtime-kernel, custom LMS, custom squeezelite, optimizations

If I talk sound experience in this article, it'll relate to above setup.

What's next on the hardware side:

  • M.2 NVME HAT 



Using a M.2 NVME SSD might surpass the USB SSD setup. On my CM4 with M.2 NVME it's been the best option. I am looking forward to give that a try. But first I need to get a little more used to my USB-Sata setup. One step at a time.


HINT:

If you intend to build a streamer I strongly recommend to look for a GPIO power filter and buffer (see image above). It'll not just filter noise from your power rail, it'll also stabilize the power rail. Usually it means more stable RPi performance under changing load conditions. It IMO even betters RPi installations with high quality power supplies like the Allo Shanti. 

Here are the ESR specs for the IanCananda ShieldPi: ESR: 2mΩ@200KHz, 0.3mΩ/@2Mhz, 1mΩ@20MHz, 4mΩ/@200MHz . That's pretty impressive.

And for the audiophiles around: You might even hear it. I do.


Conclusion 

All I can say. On the first glance not much has changed. It's still a RPi we're talking about.

Many people will ask - "Why swap?  My RPi4 runs at 2% CPU load while replaying!?!?" And that's correct. For basic streaming purposes the doubled speed is not required. I btw can confirm the doubled speed. Compiling the Logitechmedia Server went down from about 20 to 10 minutes. ;)

Do not forget though. All parts of a device and chain contribute to the audio performance. Overall quality, efficiency and speed of a device can play a big role in the game.  

Still you need to try it yourself. Systems are different, expectations are different. 

Finally. 

What about perceived sound quality - any changes on that front ?

From an audiophile perspective the new RPi5 based setup beats my RPi4/CM4 setups hands down. I consider the new setup a worthwhile step up on the audiophile ladder. What I achieved exceeded my expectations.
The sound stage became deeper, wider, cleaner, more 3D/airy. The low-end sounds ended up to be pretty impressive clean and dynamic. Overall the sound once again became more neutral and transparent. 

Yep. It seems there's no end to it. It somehow always gets a little better.

Keep in mind though. I am running an exclusive platform that's highly optimized for audio. There's no other RPi based SW platform I am aware of out there that would be able to challenge my setup. If you decide to go for an RPi5 you might experience lesser gains. 

In my experience every little change still makes an audible  difference, even on my rather modern DAC and also the new RPi. If you change the CPU clock frequency (I did), if you use a different SSD (I did) , asf, asf - you might hear slight differences. Different platform setups will perform differently though. Keep that in mind!

All I can say. From my audiophile perspective I consider the whole project a major success already now. There's simply no looking back. My entire RPi4 fleet is sent to retirement.


Enjoy.

2 comments:

  1. Nice, I keep thinking I should get me a peice of the pi.

    ReplyDelete