> Huh?  How is speed any less useful information than the type of CPU?

You can answer that question yourself.  Just grep for I386_CPU,
etc. in the code.

The kernel actually changes how it operates (to some degree) depending
on the type of CPU.  It does not do so based on the actual speed of
the CPU.

That means any code in the kernel which does this is effectively dead
weight.  That's why *I* never implemented it.