Maybe they just couldn't fit 67?

Maybe 2 higher-powered primary threads + 64 aux threads or something. I don't know how that makes sense as part of a single core but I don't have a better guess.

That's what it is, as shown on slide 6 (Die Architecture). Personally I would call this 16 big cores and 32 throughput cores but for some reason Intel is calling it 8 cores.

Yes it is. They have four 16 thread pipelines, and two single thread pipelines per core. 4*16=64 and 64+2=66

So, why do they consider that 1 core? Isn't that more like a "compute complex" of multiple cores, as seen on zen 2, but with different core architectures attached instead of 4 cores of the same design?

I'd be inclined to call them multiple cores myself, but if they all share the same pipe to main memory that would be a plausible reason to call them all the same core.

Look at slide 6, "Die Architecture" (https://www.servethehome.com/wp-content/uploads/2023/08/Inte...).

The diagram shows 8 gray boxes (in 2 columns of 4). Each gray box is a core.

Above that is a detailed view of what each core looks like. There's a middle section labeled "Crossbar", and above that are 3 boxes labeled STP, MTP, and MTP. Below that are another 3 identical boxes. So each core has 4x MTPs and 2x STP.

What are those? The text of the same slide says MTP is "Multi-Threaded Pipelines" with "16 threads per pipeline" and STP is "Single-Threaded Pipelines" with (self-evidently) 1 thread per pipeline.

And 4 * 16 + 2 * 1 = 66, so 66 threads per core.

Good one. These presentations are like 30 min each so it is hard to stay on top of all of them.

66 = 64 slow GPU-like threads + 2 very fast CPU-like threads