Let's compare the x86 ISA to, say, a Ford Model T, and a reasonably modern RISC ISA (SPARC, PowerPC, MIPS, etc.) to, say, a Ferrari. The latter is newer, pretti

Let's compare the x86 ISA to, say, a Ford Model T, and a reasonably modern RISC ISA (SPARC, PowerPC, MIPS, etc.) to, say, a Ferrari. The latter is newer, prettier, and inherently faster. However, this Model T is so successful in terms of sales that Ford has been able to hire a bunch of engineers to figure out how to add a bunch of structural reinforcement and replace the original engine with a couple of turbojets. Now the Model T looks even cruftier than before (it's got jet engines bolted on!!) but it's now at least as fast as the Ferrari.