These two improvements both carry energy use and size penalties, but these could certainly be accommodated in a laptop form factor. Of course, Apple will also be working to improve the more fundamental design elements of its CPUs, making each core more powerful even at the same clock speed. However, while Apple is improving the performance of its chips to get near the current MacBook Air range, Intel will be bringing the energy usage of those same chips down to get that kind of performance into tablets - the opposite approach to Apple.
The current MacBook Air chips use up to 15 Watts of power, while the kind of chips in the iPad typically use more like 4 Watts, though this can rise under heavy loads. That's a big advantage to Apple, but Intel's next generation of chips, codenamed Broadwell, looks set to drop energy use by at least 30% while still offering good performance boosts.
Intel has also dabbled in versions of the current generation Core i5 chips that can use just 6W of power under lighter loads, and 11.5W when under stress. Interestingly, though, this shows that Intel's performance currently doesn't scale down as well as its power use, with that chip only outscoring the A7 in Geekbench benchmarks by 30%.
Processor performance
When it comes to processor performance, currently it looks like Apple could take the advantage in the balance of performance and energy use in the gap between the iPhone/iPad and the MacBook Air, but when you get into the flexibility needed to make chips that scale from phones and tablets up to laptops, Intel has huge advantages.
The fabrication plants it uses to build its processors are years ahead of those Apple uses in terms of creating smaller, less energy-hungry components, and can produce components capable of running at lower voltages. By the time Apple can make its tablet CPUs start to compete with Intel's current laptop range, Intel will have moved on, and may be putting chips of the current level of performance in tablets.
But does the balance of power shift if the processor becomes less important? The Heterogenous System Architecture (HSA) standard is a guide for building the kind of system-on-a-chip that Apple makes, but places a much larger emphasis on using the graphics processing unit (GPU) for general computing more often, instead of relying on the CPU for almost everything. The reason is that, though the CPU is good at many tasks, it works by processing things serially, working through a problem one step at a time.
The GPU is designed to work in parallel, computing large amounts of data in intensive tasks simultaneously. It can not only do these kinds of tasks faster than a CPU, but much more efficiently too, literally using less power to do the same job.
Not all computing tasks will benefit from being on the GPU, but the idea is to make sure than any that can be made faster by going there do so, rather than just having the CPU do everything out of convenience - even if they're small tasks such as gesture recognition or face detection. It's unlikely that Apple will use the HSA standard exactly, but may implement many of the ideas in a similar way.
Intel, being better at processors than graphics cards, is not certain that HSA is the future, unsurprisingly. Like its processors, Intel's GPUs are more powerful than those Apple uses, but the PowerVR Series 6 GPU in the iPhone 5s is the most powerful in the mobile market, and is designed to scale up easily. It's currently about eight times slower than Intel's GPUs, but if you used a faster version of the PowerVR Series 6 GPU, and used 20 of its 'clusters' instead of the four in the iPhone 5s, you could match the raw computing performance of Intel's current GPUs.
