Are the prices of these CPUs comparable to x86 CPUs with similar performance?

In a sense they are, because with those core counts, you're comparing to Epyc and Xeon, which are similarly very expensive.

What they're really missing is a midrange product for a midrange price. I can't blame them for avoiding the low end, but can't I get anything for less than $2000?

While you're right, that's certainly not by choice but rather stems from the fact that right now, workstation-class OpenPOWER boards are a rather small market. You have to design the board for this server-class chip and break even on the costs for that + manufacturing a board that can actually hold these kind of chips.

So while it's unfortunate, it's not a case of ignoring the low end deliberately but mostly flows from the economic realities of not having anywhere near the addressable market of x86 or ARM. The small community of ppc64(le) enthusiasts is very much hoping for a future where this changes, however small that chance might be...

I've just tried looking on ebay. Nothing is to be found at decent (as in decent for tinkerers) prices.

This is what Microwatt is intended to address, though you have to synthesize it yourself. With luck Arctic Tern will give you the playaround board you'd like. https://www.talospace.com/2021/10/first-flight-of-kestrel-fp...

Catch 22: Either the hardware could still be used in some system, so used stuff is expensive because some companies pay through the nose for spares, or the hardware is way too old for that, in which case it's an expensive collector's item. If it's very old and common it goes in the crusher.

This seems to be universally true for all kinds of UNIX workstations and servers.

> If it's very old and common it goes in the crusher.

Repeat until the hardware is rare and worth something?

They’re more expensive, especially factoring in the motherboard. But as a sibling points out, it’s not like HEDT is inexpensive from any vendor.

and you can get a 64 core AMD Threadripper 3990X with 128x PCI-e v4 which makes the Talos II very moot.

While that may be true from a cost/performance point of view, the point of the Talos is to keep the system as transparent as possible (schematics, open source firmware etc.). If that is not a concern for you it doesn't matter I guess. But for some people it is, and the Talos is the most attractive board out there from a performance point of view if that kind of transparency is a thing for you.

The customers picking up Talos II boards won't be interested until you can show them a threadripper/epyc system with coreboot.

IIRC some of the latest AMD boards to end up with coreboot support is using opterons from 2011-2013.

I don't think you understand the point of the talos

When did they make Threadripper open source?

Neither processor is open source

Precisely. Since there's no equivalent of the Power ISA in "x86 land", it's hard to make a direct comparison (I don't believe that formally Intel or AMD consider themselves to share an architecture, and they both have slightly different instruction sets), but the closest comparison would be if AMD or Intel released the source code for PSP or ME respectively, along with all other ancillary firmware and documentation for the bring-up procedures so that, without an NDA or business agreement, a third party could design a motherboard around a Threadripper or Xeon CPU, provide that to a customer, and allow the customer to make modifications to the firmware running on that motherboard.