I was recently shopping CPUs and noticed the large number of instruction sets that both AMD and Intel support these days and was wondering if perhaps they were to eliminate some of the older, irrelevent ones could they improve speed and efficiency much like ARM has been able to do with their RISC processors? Since new Intel and AMD CPUs (or APUs) come with integrated graphics could MMX for example be eliminated?
x86 processors have been internally RISC and externally CISC (instructions from memory) since the Pentium Pro era of ~November 1, 1995. The AMD K5 could probably also be considered part of the 6th generation of x86.
RISC isn't new.
ARM is 'new', I doubt they have half the registers of an Intel or PowerPC processor though.
- More registers == better performance (usually).