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Comment by bryanlarsen | Hacker News Reader

In today's marketplace, there's very little about the ARM instruction set that makes it better suited for low power applications. Yes, it is a saner instruction set than x86, requiring less silicon to convert into uOPs, but the difference is trivial in 2012.

The difference between x86 and ARM on the power/performance curve is almost purely due to design choices and trade offs. So why not create a new low-power x86 core instead of a new ARM core?

The only way this makes sense to me is for this to be a stepping stone into the mobile market. The mobile market is definitely stepping up the power/performance curve, and AMD's experience with GPUs may be a distinct advantage for them in the mobile market in the future.

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> In today's marketplace, there's very little about the ARM instruction set that makes it better suited for low power applications.

So it's just a coincidence that ARM powers 95%+ of smartphones? I think not.

Given Intel's advantage in fabs and process technology I think it's all the more striking that to date they have failed at developing chips to effectively compete with ARM in the mobile market.

x86 is an ugly and inefficient ISA compared to ARM but it didn't matter as long as users plugged their computers into the wall.

"So it's just a coincidence that ARM powers 95%+ of smartphones? I think not."

ARM designs have been optimized for low power. x86 designs have been optimized for high speed. It has little to do with the architecture and lots to do with the design.

Nobody has ever tried to design a sub 1 watt x86 design. Nobody has ever tried to design a 100 watt ARM.

Only very recently have we had anything that's close to comparable. Medfield has a similar power rating to high performance ARM designs, and similar performance.

Intel tried the low-power x86 with the Atom, didn't really go anywhere. It's true that scaling up an ARM will be equally problematic. But, the point is that they use ARM because they don't want to push the power envelope.

Atom didn't go anywhere because it was a 10W processor benchmarked against 100W processors when running performance tests, but compared to 1W processors when doing battery tests.

It's not really a fair comparison. Atom was an attempt to hug the low-end of the computing market with a low-power CPU for use in netbooks. ARM on the other hand is a smartphone/tablet system-on-a-chip which is in a completely separate performance/power-usage realm. Different design goals, different tradeoffs.

However, Intel found out that the power/performance tradeoffs for the original Atom were not what the market wanted and they've continued to evolve the design. Today there is the "Medfield" Atom system-on-a-chip which is already making its way into smartphones and already giving ARM a run for its money. Given Intel's history and their initial level of success with this first generation SoC design it's definitely far too soon to write off Atom and bask in ARM triumphalism.

So Intel just hasn't bothered to getting around to designing a low-power x86 chip that can compete in mobile devices with ARM? The more likely explanation is that it can't be done because ARM is a better designed and therefore intrinsically more power efficient ISA than x86.

In any case, the more pressing problem for Intel is that in the mobile space consumers don't know or care what types of chips are in their phones so even if Intel could design an x86 chip competitive with ARM, consumers are unwilling to pay a brand premium for Intel that they're used to getting in the desktop market.

Intel recently released its "Medfield" SoC. It beats ARM cores at similar power envelopes, and is currently available in a few phones.

Of course, it's a single-core processor as opposed to the double or quad core ARM processors that it's up against, but the point is that they're getting quite close.

> Nobody has ever tried to design a sub 1 watt x86 design.

Transmeta tried and succeeded.

Note that this announcement is based on a processor license, not an architecture license - AMD are using an ARM design off the shelf, not designing their own new ARM core.

Yup, I had read the article the other way around. Designing their own ARM core didn't make much sense to me. Using someone else's does.

Considering AMD is now a fabless chip design shop, not doing any design work doesn't make sense to me. What is their value add? They may as well have ordered a shipment of completed processors from Nvidia.

In this case, the value add is the processor interconnect fabric. In other cases, it will be their GPU.

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