> First of all - welcome to RWT, glad to hear your perspective.

Thanks.

> My guess is that everything you say is true...

Eh, I just thought I'd post what I heard from a guy who supposedly worked on Zen.

> and that AMD isn't intending to hit the HPC
> market. They have 128b vectors (since that's all ARM supports), which simply isn't wide
> enough to be competitive with Skylake. So giving up on a third AGU makes sense. The third
> AGU is probably most helpful for HPC (where they cannot compete anyway) and isn't a particularly
> small unit in terms of design complexity and impact on the load/store buffer.
>
> David

128bit FP pipes seem optimal for most desktop and server software. HPC is pretty much the only place where latest instructions are used and even if zen was competitive here I don't think anyone would want to switch from Intel.
Personally I just hope the lack of 3rd AGU won't cause problems in SMT. I don't think normal workloads have that many operations that access memory, but SMT aims to maximize utilization of all available resources and only 2 AGUs might be a problem there.