Ronald Maas (rmaas.delete@this.wiwo.nl) on August 10, 2014 10:56 pm wrote:
> juanrga (nospam.delete@this.juanrga.com) on August 8, 2014 10:49 am wrote:
> > E.g. a x86 decoder is more difficult to implement than an ARM64 decoder, because the former has to match
> > instructions of variable length. Also the x86 ISA is full
> > of legacy instructions, which have to be implemented
> > in hardware and then verified/tested which increases development costs and time of development.
> >
> > According to Feldman an entirely custom server chip using the ARM architecture takes about 18 months
> > and about $30 million. By contrast, it takes three or four-year time frame and $300--400 million in
> > development costs required to build an x86-based server chip based on a new micro-architecture.
> >
> >
>
> An interesting video confirms what you are saying. Search for: Jim
> Keller On AMD's Next-Gen High Performance x86 & K12 ARM Cores.
>
> Saw this couple of months, but if my memory serves me correctly, he said that with the
> same transistor budget he is able to build a faster core with Aarch64 than with x86_64.
> Time will tell if that is true, but Jim seems to know what he is talking about.

Yes, he mentioned that the ARM64 ISA is more high performance than x86-64 because of three-operand, larger number of registers, and other stuff. He also mentioned the intrinsic efficiency of the ARM ISA, which allows the engineer to spend more transistors to get performance (whereas in x86 those transistor have to deal with legacy stuff and inefficiencies of the x86 ISA) and finally he mentioned that his new ARM core will have a bigger engine that the sister x86 core.