Fubarberry already posted a SteamDeckHQ article about this but I wanted to highlight the direct sources.
Per Valve in their Steam Machine FAQ:
If I don’t get a Steam Machine right away, is there anything else I can do?
Thanks to the openness of the PC platform, there are lots of options for devices that will allow you to run games natively or streamed to your TV. There are many PC sites and communities out there that can help you with that. For our part, we are continuing to work toward enabling SteamOS to be used on more hardware than just ours. In fact, with the newly-released SteamOS 3.8, you can run the same code and operating system as Steam Machine on your own living-room PC using whatever PC parts you want: learn more here. Right now, only AMD GPUs are supported, but we’re working on expanding support for the future.
Haven’t installed official steamos yet, but bazzite runs great! With the 40cu unlock (well 38/40 for me), I get close to the performance of my giant 3700x/rtx 2080 combo. For AAA games, you might want to set the UMA to 6G rather than the 512Mr ecommended for general use. But maybe the official steam is handles the unified memory better. I’ve held myself back from buying more of them to leave them available to other folks short on $.
Ha! I almost bought more than one as well, but likewise decided to leave some for others (especially as they’re getting expensive).
I booted it for the first time last night to verify it worked. I will likely update the bios next and set the memory allocation to dynamic to see how SteamOS does with that.
FYI I don’t think you need to flash the BIOS for dynamic memory anymore, someone has figured out how to do it from inside Linux.
I used the links in the “Not always required” section of this page:
https://elektricm.github.io/amd-bc250-docs/bios/flashing/
You’re a gem! Thanks for that!