> On the way, 64 bits machines, with Thunderbird like, micro-decoded
> and 8086-compatible, very performant and inexpensive. Intel
> product, 8086-incompatible .......
the 86 architecture is a dinosaur, designed in 1978 to inherit features
of the 8080 which was designed in 1973, and needs to die. IA64's VLIW
architecture is far more modern, and will carry performance to a far higher
level than 64 bit extensions of the same old EAX, [EBX*4+ESI].offset stuff.
Anyways, the IA64 has a full pentium compatibility mode, and supports mixed
mode processing where you can have 64 bit code running under an extended 32
bit OS, and visa versa, so I dunno what this 'incompatible' noise is about.
as far as G4 goes, what I've read and heard is that the performance doing
regular programming is fairly poor, its only specific "SIMD" benchmarks
that achieve the high numbers Apple likes to toss around.
Anyways, to achieve really high clock rates on a complex instruction set
you HAVE to go to a deep pipeline. RISC processors got away with a
simpler pipeline entirely due to the simplicity of their instruction sets,
and even they have run into clock speed limitations that are not easily
overcome... All the current high end risc engines have had to resort to
things like super-scalar architecture and incredibly complex scoreboarding
to hide the details of the pipelines from the instruction set model, once
this has been done, the risc vs cisc arguments are somewhat silly.
-jrp
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