Raspberry Pi OS, Strike Three

Yesterday, I had a little time to mess around, and also needed to remove the USB hub from my Raspberry Pi 4 anyway (I'm putting together my gear stack for working outdoors, need a USB hub, and discovered when the one I ordered arrived that I hadn't been paying attention and it was USB C on the computer side), so I decided to test my theory that my off-brand el-cheapo USB hub was the cause of 64-bit Raspberry Pi OS's "freezes up" behavior.

It wasn't.

As with my two prior attempts (one with the OS installed on a USB drive, the second on an SD card), the machine eventually just locked up -- no mouse movement, no response to keyboard shortcuts, etc. -- and required a hard reboot. I think this time it went for about 45 minutes.

I still don't think it's a software problem. Or, rather, I think that if it's a software problem, the software is the OS itself, not e.g. some rogue browser extension. Last time around, I added no extensions to my preferred browser, Chromium-based Vivaldi, and the time before that the browser wasn't even running when a freeze occurred.

On the other hand, I am now down to pretty basic peripheral hardware. Two small HDMI TVs as monitors -- the machine's default output is HDMI -- a regular old USB keyboard, and an ergonomic mouse that doesn't have any special drivers or anything like that. There doesn't seem to be anything for the new OS to stumble on, hardware-wise.

I'm wondering if it might have to do with the Raspberry Pi hardware itself. That seems like a strange possibility since it's a Raspberry Pi machine and the Raspberry Pi OS, but my machine is not the basic build. It's the Canakit (I'm pretty sure the most reputable Raspberry Pi kit company) "Raspberry Pi 4 Extreme," which has 8Gb of RAM.

Per Wikipedia, the 8Gb version of the Pi 4B "has a revised circuit board," and "[i]n mid-2021, Pi 4 B models appeared with the improved Broadcom BCM2711C0" (as opposed to whatever previous ARM processor was used). I bought my machine in mid-2021 and don't know if it uses the older or newer CPU.

So I suppose there may be a bug running around that has to do with the "revised circuit board" in the 8Gb model as opposed to the 2Gb default, or with the CPU change. If so, I suspect it's rare, as none of the stuff I've found with web searches on Raspberry Pi freezes resembles my own specific situation.

I must say that the 64-bit Raspberry Pi OS seems to get better (until the freeze comes) with each update. Starting and running a browser keeps getting faster and smoother. It's becoming very noticeable versus the 32-bit version.

But the number of times the 32-bit version has frozen up on me is zero, and I have yet to finish a long session on 64-bit without a freeze. I can't  have my computer freezing right in the middle of some unsaved work. So 32-bit it shall remain, until the next time I get around to updating to latest version of 64-bit and seeing what happens.