[paulmd]

All Skylake-X chips actually have the second 512b SIMD unit, including the i7s. Intel's initial documentation here was incorrect, InstLatX64 determined that both units are enabled.

https://twitter.com/InstLatX64/status/935966607188295680

[BeeOnRope]

Yes, for now - but I don't think I implied otherwise?

I said Skylake-X/SP. Certainly not all Skylake-SP (aka "Scalable Xeon" or whatever Intel calls them) server chips have 2 FMA units.

BTW, I believe Intel also documents this fact about X chips on ARK now as well.