Marks Rpi Cluster continues to run 24/7. The Pi4's are doing Einstein@home BRP4 work.
Bitscope blade
I did a couple of posts about this back in Sept 2018. At the time I had purchased one and was trying to source enough Pi3's and a suitable power supply. See BitScope Blade Rack 20 (Part 1) and BitScope Blade Rack 20 (Part 2)
I've dug it out and half-built it. As I expected at the time it has a design feature in that the Blade Duo's sit too close to the Pi restricting airflow so that even Pi3's run too hot.
When I say half-built I mean I have put 10 Pi3's in it. It holds 20. I haven't assembled the other Blade Duo's and power plates, but I have put the rack and back panels together and wired it up. I had 6 Pi3's running yesterday and just need to put SD cards in the others and configure them to get ten going. The case has 4 x 30mm fans which make a lot of noise considering I have only put two of the four fans in so far.
Fast forward to 2022 and Bitscope have an updated design with fans on the Blade Duo's to improve the airflow over each Pi. They seem to be the same 30mm fans they had in the original design. I have asked for a quote so I can get the Pi4's into a single case. They still seem to use the same concept of power plates and Blade Duo's between them. The power circuitry supports voltages between 12 and 24 volts. The original that I have supports between 12 and 48 volts. Fortunately I bought a 24 volt power supply so I might be able to use it to run the Pi4's.