Re:Intel's disruption is now complete
by sidewndr46 on Saturday November 14, 2020 @12:26PM
(#25093795)
For the uneducated, what is an "OOB" here?
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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...
Yes, I was going by memory, which thought “out of order buffer” was a thing. I meant ROB. Point still stands, in that scaling these blocks is very difficult with variable instruction size.