[wtallis]

Right; it's easy to forget that superscalar CPU cores don't actually have to be in-order, but most of them are out-of-order because that's usually necessary to make good use of a wide superscalar core.

(What's the best-performing in-order general purpose CPU core? POWER6 was notably in-order and ran at quite high clock speeds for the time. Intel's first-gen Atom cores were in-order and around the same time as POWER6 but at half the clock speed. SPARC T3 was ran at an even lower clock speed.)

[gpderetta]

POWER6 might indeed have been the last In-Order speed demon.

[sillywalk]

The IBM Z10 came out a year later. It was co-designed with POWER6 as part of IBM's eClipz project, and shared a number of features / design choices, including in-order execution.