Comment by etep
12 years ago
This is not a half baked study. The right comparison is being made, namely performance versus energy. Further, they attempt normalized comparisons, here quoting:
To factor out the impact of technology, present technology-independent power by scaling all processors to 45nm and normalizing the frequency to 1 GHz.
Normalization is nice for a mental exercise, but I cannot buy a normalized phone with a normalized i7 that fits in my normalized pocket. Engineering is the art of trade-offs and the i7 has traded off size and power to achieve speed. That is great when you have an i7-scale size and power budget, but if the i7 exceeds your power or size budget it is a non-starter regardless of how efficient (when normalized) it is. Full stop.
The implicit argument of the paper is that Intel could produce a direct size+power+speed replacement for a phone-scale ARM processor, they just need to dial the knobs to small+small+slower. The counter argument is that they have tried but not come close. The Atom line is roughly comparable with respect to speed, but size and power are a problem. The Galileo processor is roughly comparable with respect to power and size but speed is horribly lacking.
There are x86 phones on the market that have similar weight/shape/battery life to ARM phones. Anandtech reviewed one two years ago and found it in the middle of the pack with respect to energy.
The question for Intel is dialing down the profit knob: how much of a hit do they want to take on each unit shipped, by competing with ARM for tiny phone chips.
Ref: http://www.anandtech.com/show/5770/lava-xolo-x900-review-the...
Unless they carefully considered issues such as memory timing, or actually ran all the CPUs at 1GHz, just scaling results by clock frequency will make the x86s look worse and the ARMs better, because the x86s have a bigger gap between core and memory speed. Anyone who has experience with PC overclocking will know this - increasing the core clock by e.g. 25% will not make any benchmark (except maybe the most trivial of microbenchmarks) result improve by that same amount, and the same goes for the other direction: A 3.4GHz i7 run at 1GHz will not be 3.4x slower. On the other hand (no pun intended), the ARMs have a native frequency closer to 1GHz and scaling their results will not introduce as much error.