This document provides an overview and introduction as to why SV (a
Cray-style Vector augmentation to OpenPOWER) exists, and how it works.
+# Introduction: SIMD and Cray Vectors
+
SIMD, the primary method for easy parallelism of the
past 30 years in Computer Architectures, is [known to be
harmful](https://www.sigarch.org/simd-instructions-considered-harmful/).
increases using "tagging" (similar to how x86 originally extended
registers from 32 to 64 bit).
+## SV
+
The fundamentals are:
* The Program Counter gains a "Sub Counter" context.