11th of April

Marks Rpi Cluster currently consists of:
2 x Pi4 model B (4GB)
2 x Pi4 model B (2GB)
14 x Pi3 model B+
6 x Pi3 model B

The two Pi4 4GB are concentrating on Rosetta work. The two Pi4 2GB are support nodes. The Pi3's are concentrating on Einstein work.


Cooling
The two Pi4 4GB models were using Pimorni fan shims for cooling but another one seized up today. I had to use a Noctua 40MM fan in its place. The Pimoroni fans only seem to last about 3 to 4 months of constant running. I have already replaced one under warranty.


Power
I purchased a number of Mean Well power supplies to run the Pi4's. I will be replacing the Pi3's with Pi4's. This power supply is the LRS-75-5 model which provides 5 volts at 14 amps which should be more than enough to run 4 x Pi4 nodes.

As you can see they are a bare-bones power supply with no wiring. I will probably have the cases 3D printed as there is nothing available that would suit them.


Rosetta tips
If you want to help with Covid-19 research and are familiar with BOINC and have a Pi4 I would encourage you to run the Rosetta@home project. See my previous blog post on how to get Raspbian into aarch64 mode and BOINC requesting aarch64 work.

Tasks need up to 1.3GB of memory (it depends on the work unit) so a Pi4 2GB could run one and a Pi4 4GB could run 3 at a time. Unfortunately the Pi3's and Pi4 1GB don't have enough memory.

The tasks have a 3 day deadline, so run a small cache setting. The project recommend 1 day, however I run mine with 0.3 days. Tasks have a fixed run time which defaults to 8 hours.

Each running task can use up to 2GB of disk space, so use a 8GB micro SD card or larger. I'm using 16GB micro SD cards. Change the BOINC setting to allow up to 6GB of disk space to be used.

To reduce the writes to the micro SD card I recommend setting the BOINC checkpoint interval to 300 or 600 seconds. Mine are set to 600 seconds