Op Anandtech staat een artikeltje van de hand van Ga'ash dat SSE (KNI) en 3DNow! met elkaar vergelijkt.
Perhaps the most touted improvement the Pentium III has over it's older brother the Pentium II is the addition of Streaming SIMD Extensions, or SSE for short. As described in Anandtech's Pentium III review, SIMD is:
SIMD, or Single Instruction Multiple Data (in this case SIMD-FP as it applies to FPU instructions, whereas MMX offered SIMD-Int for Integer instructions) allows a single command (or instruction) to be applied to multiple sets of data simultaneously. The key to understanding the benefits of SIMD-FP instructions is the emphasis on the simultaneous execution of commonly used instructions such as multiplies, divides, and adds.
Specifically applied to SSE, SIMD is the ability perform a single instruction on four pairs of 32bit floating point values in one clock cycle. Clearly, SIMD offers a vast improvement in performance; however, AMD has used 3DNow (a SIMD instruction set) for many months. What is it that sets SSE and 3DNow apart, if anything?