I think that's a typo - the Apple Silicon M1 has a "ROB is in the 630 instruction range" - https://www.anandtech.com/show/16226/apple-silicon-m1-a14-de...

"ROB" and "OOO" might have gotten mixed together here.

OOO = Out-of-order. Refers to the fact that the M1 can decode instructions in parallel.

ROB = Re-Order Buffer. Refers to the stage where the parallel instructions get put back "in-order" and "retired."

From the Anandtech article[1] on the M1, I think this is referring to the reorder buffer, or ROB. Reorder buffers allow instructions to execute out-of-order, so maybe that's where the "OO" comes from.

[1] https://www.anandtech.com/show/16226/apple-silicon-m1-a14-de...