The Free On-line Dictionary of Computing (30 December 2018):

Streaming SIMD Extensions
Katmai New Instructions
KNI
SSE

    (SSE) Intel Corporation's floating point
   SIMD extention of their Pentium microprocessor
   architecture.  SSE was formerly know as KNI (Katmai New
   Instructions).  It was introduced with the Pentium III.

   Intel Pentium III
   (http://developer.intel.com/design/pentiumiii/prodbref/).

   ipoem (http://ipoem.com/technology/Docs/pentium4.html).

   (2003-07-13)