ARM: How does it compare, exactly?

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ElFenix

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Mar 20, 2000
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Back in the day risc was known for floating point performance that used to trounce the x86 platform (depending on the application), but that simply isn't true anymore. Apple made you pay through the teeth for it which made the down sides (lack of compatibility, programing) that much more apparent.

Floating Point was their bread and butter, but if there's no programing or widespread acceptance like AMD/Intel have garnered it's really not something an end user can take advantage of for anything other than niche computing.

Dose mac even sell mac books with risc processors any more? Personally, I find it a little odd risc computing didn't garner more attention; but over the years it's always found a niche for itself.

niche? both intel and amd moved their x86 processors to a risc-stlye core with an x86 decoder in front more than a decade ago. maybe the atom isn't built that way but i doubt it.
 
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IntelUser2000

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Oct 14, 2003
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niche? both intel and amd moved their x86 processors to a risc-stlye core with an x86 decoder in front more than a decade ago. maybe the atom isn't built that way but i doubt it.

Yep, even the Atom uses the same basic architecture. The decoders are the main targets that anti-x86 folks tries to point out as its disadvantage, but nowadays, the size and transistor impact are minimal.
 

Idontcare

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Oct 10, 1999
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ARM is an ISA. http://en.wikipedia.org/wiki/ARM_architecture

Cortex A9 is a microarchitecture that implements support for the ARM v7 ISA. http://en.wikipedia.org/wiki/ARM_Cortex-A9_MPCore

POWER is an ISA. http://en.wikipedia.org/wiki/IBM_POWER

POWER7 is a microarchitecture that implements support for the POWER ISA. http://en.wikipedia.org/wiki/POWER7

Folks get tripped up by confusing/conflating ISA with microarchitecture all the time.

In computer engineering, microarchitecture (sometimes abbreviated to µarch or uarch) is the way a given instruction set architecture (ISA) is implemented on a processor.

A given ISA may be implemented with different microarchitectures.[1]

Implementations might vary due to different goals of a given design or due to shifts in technology.[2] Computer architecture is the combination of microarchitecture and instruction set design.

http://en.wikipedia.org/wiki/Microarchitecture

x86 (and x64) is an ISA not a microarchitecture. SSE4 is an ISA not a microarchitecture.

DDR-3 is a microarchitecture. NAND flash is a microarchitecture.

Nehalem is a microarchitecture that included support for ISA extensions above and beyond the ISA supported by the preceding Core microarchitecture.