I’m pleased to meet you, Zynthian and its community members!
My V5.1 kit will be arrived soon. A temporary setup is built like below. In this setup, some instruments works well, play, sounds good.
Is the heating only for me? Simply add a chain of Internet Radio, and remove the chain.
Actually, I’m enjoying the experiences with Zynthian, what a nice product!
You don’t have any heatsink, so it’s expected your pi5 gets very hot.
My experience with attempting to run Zynthian on a RPi5 without a heatsink was that it would report overheating after about 30 seconds if you tried to play almost any instrument. I say almost because I didn’t try that many, but all the ones I tried, LinuxSampler, ZynAddSubFx, SurgeXT caused overheating. Using a big box fan and positioning it near the RPi5 made most instruments OK, but not SurgeXT. Adding the RPi active cooler mostly fixed the problem except for some pad sounds with SurgeXT. The Zynthian thermal block in the V5 case did not overheat at all for me.
I never tried Internet Radio.
This is expected behaviour when running RPi 5 without heatsink.
Please do not run the RPi5 without heatsink. Please read and follow the docs.
Overtemp safety are for cases of emergency only and not meant to be triggered regularly. Once one of these fails, the board will be destroyed. Every second running without cooling reduces long-term reliability!
Sorry for my barbaric acts without heatsink. Yes, high temperature comes from lack of thermal management by myself.
Now I add a little convection, it makes system temperature below 55.0 ºC. I should wait gently, an arrival of V5.1 kit.
I am worrying about 100.0 %CPU of python3 shown in top command, after remove the chain. This is the true question what I thought.
The pi5 is a considerably different beast to the pi3&4 where zynthian cut its teeth. This is without doubt the largest change and there are still aspects of the development that are emerging. Personally, I’ve held off upgrading to 5 as yet because all my devices are self builds and I haven’t got any of the modern kits that have been tested in the field and are known to work and are used for testing.
I will upgrade devices like the cajon(see past posts) but I will wait for a self build consensus to emerge before doing so. It’s my approach, your work is the sort of thing that helps and encourages my development by demonstrating the differences.
Maybe it got hot and bothered because you cut it off half way through a song it was listening to?
Please use the “Report Issue” button in webconf to detail what is happening. It sounds like something is getting into a loop that it shouldn’t and we should fix it but there is too little info in this thread to know where to start looking. CPU should not remain high after removing a chain but it might spike whilst it performs some temporary operation during the removal stage.
I was in a cafe eating breakfast last week when that was happening. Lots of really good rock music but interrupted part way through each track. The indignation almost gave me indigestion.
@riban Thank you for your attention. Noted as Issue #1437.
Then I am ready to listen my little Zynthian who thoughts.
Have you try running without VNC?
It’s only the internet radio what causes the issue? I see ffmpeg is still running and It shouldn’t. It should be killed when internet radio is removed.
Regards
No, I have not yet. I still be in a front of VNC.
I would bet that a dedicated display may turns %CPU into normal rate. I’m facing a time to purchase an adaptor between male-micro-HDMI and normal-HDMI. It is a head for headless 
And I have tested little deeply only two generator; Test Audio Generator and Internet Radio.
My little Zynthian tells me some information via debugger. Internet Radio leaves proc_poll_inetradio in callstack after its chain removed. It doesnt like a Test Signal Generator.
proc_poll_inetradio executed /zynthian/zynthian-ui/zyngine/zynthian_engine_inet_radio.py L180, I guess it does buffering. Finally I got low %CPU consumption with an exception I have injected. Yes, I know it is a bad behavior of me.
I’ve tried with Vangelis, but I can not reproduce the problem on a Zynthian with proper cooling.
Maybe it is really only due to missing cooler that @g.tezzie experiences such problem.
It could happen like this:
I think there is no bug like the one reported. It is just how a frying CPU acts with safety triggered.
The Internet-Radio can be loaded or tossed any time without any glitch on a RPi5 with minimum adequate cooling…
Naked pi5 made me A-CHI-CHI
@fussl, thank you for sharing your validation result. I’ve observed the same moderate temperature results as yours with my V5.1 + oram2506.1.
@jofemodo, the aluminum chassis of the V5.1 effectively dissipates heat. Despite a high workload, it only gets warm, not hot.
Regarding the high CPU usage of python3, it likely stems from the polling loop within proc_poll_thread_task(). It seems that socket.recv() returns an empty byte array (e.g., b'') upon a closed connection, rather than raising a TimeoutError. I’ve added a break condition for b'' and achieved good results on my end.
Here’s a link to my commit: #1437 : Add break condition for closed connections · g-tezzie/zynthian-ui@2742bd6 · GitHub
Jeje! That’s the goal! We did intensive tests to be sure it never gets too hot, even working with the almost-oven July temperatures of the spanish mediterranean cost You can always touch the V5 case without risk of harming your hands. Thanks for confirming! 
Note that if it really gets too hot, you always can use an external usb desk-fan to increase the heat dissipation in the alucase. I never need it, but it’s a very effective and simple solution for extreme cases:
All the best,
Please, send a PR to vangelis branch.
Thanks!
+1 The heat generated by a Pi5 is the reason why Zynthian miniaturisation is very limited if it can be only passively cooled. With active cooling there might be potential for miniaturisation, but will need a noisy pong whacker.
The zynthian-pwm-fan service actually turns a noisy fan into something barely perceptible.
This is my PR: Internet Radio: Add break condition for closed connections. by g-tezzie · Pull Request #530 · zynthian/zynthian-ui · GitHub
Please review the PR. Any feedback is welcome.
