Hardware

Took a while for games to use MMX

Even Intel's 1st iteration of MMX was a kludge, as it used the floating point unit, so you could either use FP, or MMX, but not both simultaneously o.O

Took awhile for that to be separated and gain the benefits of both available together.

Intel also added 57 new instructions specifically designed to manipulate and process video, audio, and graphical data more efficiently.

These instructions are oriented to the highly parallel and often repetitive sequences often found in multimedia operations.

Highly parallel refers to the fact that the same processing is done on many different data points, such as when modifying a graphic image.

The main drawbacks to MMX were that it only worked on integer values and used the floating-point unit for processing, meaning that time was lost when a shift to floating-point operations was necessary.

These drawbacks were corrected in the additions to MMX from Intel and AMD.

https://www.informit.com/articles/article.aspx?p=130978&seqNum=7