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Comment by vibrunazo | Hacker News Reader

It's an i5 processor, 2 cores at 1.8ghz. New generation arm processors, for example the tegra 4, is quad core at 1.9ghz.

Wouldn't it be both more powerful and have more battery life, if it had waited for the tegra 4? Or am I missing something?

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Yes you are missing something. Processor performance is not simply a function of number of cores and clock speed. There are vast differences between arm's architecture and x86.

How could we compare then?

Benchmarks.

I don't know what benchmark would give an unbiased comparison.

Build your own benchmark. Measure whatever you want to do. Or if you insist on standardized testing, use something like SPECInt 2006. Results here: http://www.spec.org/cpu2006/results/res2013q1/ (sadly no ARM results). Of course that is only for integer calculations, if you need fp, use SPECfp.

There's nothing that you can really condense down into a couple of simple numbers to use in marketing to non technical people.

Actually comparing Arm versus x86 is really like comparing apples to oranges. One is RISC, other is CISC. One is good with running multiple threads on single core with highly sophisticated branch prediction, other concentrates having many low powered cores each hoarding threads. And this is very, very crude simplification.

Benchmarks tend to be always favor other camp, depending which attributes you are testing.

Actually Intel chips are since long RISC based, with a CISC translation layer. The real difference is in the more advanced pipeline, prediction and cache and and of course the 32 vs 64 bit + other architectural features. Hence the intel chips use a lot more power than an ARM based processor.

This is not exactly true. In most cases intel's chips are more power hungry but the low power atom processors bring better performance than an ARM cortex A9 while still having lower power consumption. (mostly by racing to sleep faster) And this is a three year old architecture i'm talking about.

link for the curious:http://www.anandtech.com/show/6529/busting-the-x86-power-myt...

You are missing something. 2 things, actually.

Cache and instruction set.

Intel is still more powerful than ARM because of its instruction set.

What makes the x86 instruction set more powerful than ARM?

It's CISC rather than RISC, and ARM chips are also designed to use as little power as possible, reducing performance.

I don't see how being CISC rather than RISC results in any inherit advantage. "The CISC approach attempts to minimize the number of instructions per program, sacrificing the number of cycles per instruction. RISC does the opposite, reducing the cycles per instruction at the cost of the number of instructions per program."

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