Trying Raspberry Pi OS 64 bit

I received a Pi4 8GB so thought I would try it using the new Raspberry Pi OS 64 bit. At the moment there is only a full version. Normally I use Raspbian lite as my Pi's are running headless (no screen or keyboard). It just means its a bigger download.

It installed as normal and the setup process is just the same as for Raspbian. After I got it going the first thing I did was to remove the desktop with a "sudo apt remove x11-*" command followed by a "sudo apt autoremove". Then I updated it with a "sudo apt update && sudo apt upgrade" command as there are a few updates. After the updates and a reboot it reports:

Linux *** 5.4.42-v8+ #1319 SMP PREEMPT Wed May 20 14:18:56 BST 2020 aarch64 GNU/Linux

That means its running a 5.4 kernel. For comparison Debian buster is using the 4.19 kernel. Here is the output from a free command to see how much memory its got:

              total        used        free      shared  buff/cache   available
Mem:        8054896     1421728     4474672         380     2158496     6507884
Swap:        102396           0      102396

Given its really running Debian adding buster-backports is a 1 line change to /etc/apt/sources.list and adding "deb http://deb.debian.org/debian buster-backports main" to the end, without the quotes. There is no need to add signing keys because its already using the Debian repositories.

Getting the latest BOINC is a simple matter of typing "apt install -t buster-backports boinc-client" which will get you the 7.16.1 version as I type this.

There is no need to use an <alt_platform> tag in the cc_config.xml to get aarch64 apps. I did have to download the aarch64 Einstein BRP4 app written by user N30DG and install it. Unfortunately I did this before I had attached to the Einstein project and had an issue with ownership of the einstein projects folder. A "sudo chown boinc:boinc /var/lib/boinc-client/* -R" command fixed that.

I've run one Einstein BRP4 task through using the optimized app. Run time was around 3 hours. By comparison the 32 bit app from the project takes 7 hours. Memory usage was 193MB using the optimized app compared to 133MB for the project app. That means its possible to run 4 at a time on a 1GB Pi3. I will have to try that some other time.

I have 3 Rosetta tasks running on it at the moment (they were running at the same time as the Einstein task). They normally take 8 hours and have been going for 3 hours now.

Overall its a much better experience than trying to run Raspbian with a 64 bit kernel. The extra memory will come in handy for the Rosetta apps, some of their work units use 1.5GB. With my Pi4 4GB I have had to limit them to only running 3 tasks at a time. As this is still considered beta expect frequent updates as the Raspberry Pi foundation resolve issues.

Update - 5 July
I have converted all the Pi4's to Raspberry Pi OS (64 bit).

One bug I noticed is if the Bluetooth and WiFi modules are blacklisted it complains about /dev/wifi not being accessible to rfkill. It doesn't complain under Raspbian.