We aren't talking about being more power efficient than IBM's desktop workstation architecture of the 90's.
What we're talking about is the thing that Apple puts in laptops. And there is a reason they switched to Intel and not ARM at the time when they did.
We're talking about having better power efficiency than ARM.
There are two classes of ARM processors you could be talking about.
One is the kind they put in low end Android phones. These have excellent performance per watt because they prioritize efficiency over performance. They are thereby slower.
The other is processors with performance competitive to Intel Core processors. The only ARM processor in this class is Apple's, and it has a process advantage.
However, to attempt to break into that market, Intel intentionally sold their chips at a very large loss for quite some time.
This is confusing two things.
One is how much it costs to manufacture a chip vs. how much you sell it for. The other is the net profit or loss of the business unit, including the R&D cost of developing the microarchitecture.
Intel's problem with Atom isn't the performance per watt, it's the price/performance. It's too slow for how expensive it is. It's not that much faster than much cheaper ARM processors, so nobody wants it for that price. What they were asking was so excessive that even after heavily discounting it, it was still too expensive. The only place it really got used was netbooks running Windows where being x86 was the thing that made it worth the premium. So they never reached the volumes needed to recover the R&D.
To compete with low performance ARM processors in the low end of the market, you have to compete on price. Intel doesn't want to do that, but nothing else will work there, because that market is highly price sensitive.
In the high end mobile market, i.e. workstation-class laptops, Intel had the best performance per watt up until the point that they lost their process advantage. Before then no ARM processors in that market had better efficiency because no ARM processors in that market existed.
Comments
What we're talking about is the thing that Apple puts in laptops. And there is a reason they switched to Intel and not ARM at the time when they did.
There are two classes of ARM processors you could be talking about.
One is the kind they put in low end Android phones. These have excellent performance per watt because they prioritize efficiency over performance. They are thereby slower.
The other is processors with performance competitive to Intel Core processors. The only ARM processor in this class is Apple's, and it has a process advantage.
This is confusing two things.
One is how much it costs to manufacture a chip vs. how much you sell it for. The other is the net profit or loss of the business unit, including the R&D cost of developing the microarchitecture.
Intel's problem with Atom isn't the performance per watt, it's the price/performance. It's too slow for how expensive it is. It's not that much faster than much cheaper ARM processors, so nobody wants it for that price. What they were asking was so excessive that even after heavily discounting it, it was still too expensive. The only place it really got used was netbooks running Windows where being x86 was the thing that made it worth the premium. So they never reached the volumes needed to recover the R&D.
To compete with low performance ARM processors in the low end of the market, you have to compete on price. Intel doesn't want to do that, but nothing else will work there, because that market is highly price sensitive.
In the high end mobile market, i.e. workstation-class laptops, Intel had the best performance per watt up until the point that they lost their process advantage. Before then no ARM processors in that market had better efficiency because no ARM processors in that market existed.