I'm trialing using AArch64 for desktop use. I bought a Raspberry Pi 4 4GB desktop kit awhile back and it sucked in the beginning. So I did what most people do with their pi; that is to leave it unused and unplugged like a Nintendo Wii.
Finally after the firmware fixes came about to improve cooling a few months ago and it was advised to just run the thing set up on its side, I decided to revisit running a 'desktop' on it.
Raspbian, as most people know, is 32-bit and the idea is you can plug the microsd card it into any model of pi ever made and it'll run. This sucks for performance and you can't run a version of firefox made the past few years. Chromium isn't an option on a 4GB ram system, it's just not.
I eventually settled on using sakaki's gentoo pi64 build and it was fairly painless to get running. Unfortunately, she hasn't kept the build up to date and there's a lot of weird customization she performed to get things running in the early days.
Anyways aside from having it run some compiles overnight and finding a new binhost to pull prebuilt stuff from, it runs pretty well. Actually better than my Intel Atom powered GPD Pocket (as it does not throttle ever). All the hardware works, and I've had no video issues since switching to the 5.4 kernel. It checks most of the boxes that OP asked for aside from the RAM being limited to 4GB. Unlike more powerful options on the market, it's got a wide release and a low price point so developers will be working on it.
So yeah, there's your AArch64 desktop you can buy today that everything works on for around $50. If you want to improve performance a bit more for IO, there's SSD/nvme adapters for it, and while I'm unsure about hooking into pci-e, the device has it...
Oh, and the audio thing is dumb as hell to complain about. Just output the audio through HDMI to your receiver and call it a day. What's the big friggin deal that the desktop lacks a 7.1 analog output. If you want high quality headphone audio, USB audio is practically plug and play on any OS these days. I don't get it.
Ubuntu is probably the way to go on the Pi if you're looking for compatibility. The 32 bit version is ARMv7 instead of ARMv6 with HF packages as Raspbian is. The 64 bit version is ARMv8. It's an official version from Canonical so you don't have to worry about some person abandoning their build or compiling your own packages all the time. With the newer CPU in the Pi 4 it's possible for them to support >4G models in the future but they aren't really interested in targeting $100+ use cases so it'll never make a "great" desktop. Useful as a fanless device that can run standard code though.
If you hack into PCIe you'd lose the USB. It's only a single x1 connection. I suppose you could hack a PCIe switch on top of that but even so it's x1 so it was already oversubscribed just hosting the USB 3 interfaces.
I don't know, probably adds to my CPU overhead a little and I don't feel like doing that.
Not using chromium or electron apps helps my RAM situation pretty strongly. The only time I run OOM is if the pi is doing on-device compiling with too many threads. I run a modest 8-12 firefox tabs. Usually just over half the ram is utilized throughout the day.
> Oh, and the audio thing is dumb as hell to complain about. Just output the audio through HDMI to your receiver and call it a day. What's the big friggin deal that the desktop lacks a 7.1 analog output. If you want high quality headphone audio, USB audio is practically plug and play on any OS these days. I don't get it.
Dude, audiophiles run complicated setups. Maybe their receiver doesn't take HDMI and they'd prefer to route that to the TV. Maybe they're using analog amps from the 70s that take 1/4" balanced TRS. Maybe lots of things. That thought process is exactly the kind of thinking that leads to rigid, inflexible designs that lock people into parts or hardware they don't want to use
> Measurable with an oscilloscope though. Not your ears.
Admittedly I’m running a pretty budget setup, so modern systems may have improved measurably, but I’ve noticed on both my desktop and my laptop (with 2010 Intel 5 Series chipsets) the onboard audio line out gets really noisy, so much so that I can hear different kinds of buzzing when I move the mouse and scroll :) Wouldn’t call myself an audiophile by any means either, haha.
Some devices have decent analog outputs. Apple's had a good history with their laptops. Most suck, all of the pi's analog outputs suck, there's too much noise and they don't have proper amp circuits and so aren't able to maintain full frequency response under a load. I wear IEM's that are extremely sensitive, so any noise gets picked up inside the system if it's not well isolated, yet because of the earlier mentioned problem they won't get full bass response. This leaves the sound very thin and noisy.
But that wasn't even my point. My point was: Any sort of sound being sent out of the device should be digital (pci-e to a sound card, USB to a headphone DAC, or HDMI/toslink/coax to a receiver). All of those options mostly eliminate the noise problem when done right.
Finally after the firmware fixes came about to improve cooling a few months ago and it was advised to just run the thing set up on its side, I decided to revisit running a 'desktop' on it.
Raspbian, as most people know, is 32-bit and the idea is you can plug the microsd card it into any model of pi ever made and it'll run. This sucks for performance and you can't run a version of firefox made the past few years. Chromium isn't an option on a 4GB ram system, it's just not.
I eventually settled on using sakaki's gentoo pi64 build and it was fairly painless to get running. Unfortunately, she hasn't kept the build up to date and there's a lot of weird customization she performed to get things running in the early days.
Anyways aside from having it run some compiles overnight and finding a new binhost to pull prebuilt stuff from, it runs pretty well. Actually better than my Intel Atom powered GPD Pocket (as it does not throttle ever). All the hardware works, and I've had no video issues since switching to the 5.4 kernel. It checks most of the boxes that OP asked for aside from the RAM being limited to 4GB. Unlike more powerful options on the market, it's got a wide release and a low price point so developers will be working on it.
So yeah, there's your AArch64 desktop you can buy today that everything works on for around $50. If you want to improve performance a bit more for IO, there's SSD/nvme adapters for it, and while I'm unsure about hooking into pci-e, the device has it...
Oh, and the audio thing is dumb as hell to complain about. Just output the audio through HDMI to your receiver and call it a day. What's the big friggin deal that the desktop lacks a 7.1 analog output. If you want high quality headphone audio, USB audio is practically plug and play on any OS these days. I don't get it.