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The "mysterious" XMOS part looks like this:

http://www.xmos.com/products/silicon/xcore-200

If it had a DDR3 interface, it'd be cool if it were the CPU. It'd be more Amiga-like.

The XMOS devices are simply multicore microcontroller-level parts. Basically, you're going to be using them for low-latency, highly deterministic functions like audio processing. Possibly enough throughput for video tho @500MHz.

> up to 32 logical cores

Wait, are there a bunch of real, independent cores on this thing, or are they doing heavy amounts of SMT?

The specific chip in use here has two actual cores each with up to 8 hardware threads ("logical cores" in current XMOS marketing parlance). The hardware executes instructions from the active threads in a round-robin fashion. Due to pipelining, there has to be at least 4 clock cycles between two instructions from the same thread, so maximum per-thread speed is 1/4 the overall clock speed and you can execute up to 4 threads on each core with no further slowdown. Also, the hardware cores don't share memory and communicate only via message passing, and the threads generally communicate in the same way. It's an interesting architecture which no-one's really made any use of on AmigaOne hardware for the whole 5 years it's been shipping with it.

Yes. There are a bunch of cores, plus SMT. The datasheets for their parts give equivalent performance depending on how many threads you have. XMOS chips are in that category of Neat and Weird, which is perfect for an Amiga type system.

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