> Adding 64-bit wide paths adds a lot of silicon for
something that would currently not get used at all,
and in the future won't get used much for quite some
time.
I can't find the quote, but John Mashey said that adding 64 bit support to MIPS processors cost something like 5% area. Datapaths and architectural registers really aren't that expensive in area or power.
It does takes more power to move 64 bits across the pins and 64 bit addresses take more space. I suspect that those factors are far more important wrt battery and cell phone cost than the processor costs.
I can't find the quote, but John Mashey said that adding 64 bit support to MIPS processors cost something like 5% area. Datapaths and architectural registers really aren't that expensive in area or power.
It does takes more power to move 64 bits across the pins and 64 bit addresses take more space. I suspect that those factors are far more important wrt battery and cell phone cost than the processor costs.