Intel Vs ARM

For sometime now, Intel’s Penwell project has been threatening to change the landscape of the Telecom industry. And finally it is here. Just to know what that actually means, we need to take a look at the current scene.

A PC consists of a motherboard chipset typically split into a “northbridge” that connects to the processor and memory (e.g – Intel’s P45) and “southbridge” that connects to various peripheral buses like PCI-Express, USB etc (e.g – Intel’s ICH10R), a CPU (e.g. – Intel Core 2 Duo), RAM, Hard Drive or a solid state disk, GPU (e.g. – ATI Radeon HD5890, Power Supply and several peripherals connected to the PCI or PCI-Express buses (e.g. – built in sound chipset or wifi card)

Smart phones have all of the above components, except they are more integrated – a few main chips contain the CPU, GPU and other specialized coprocessors, motherboard buses, memory controllers, LCD controllers, sound chipset, CMOS Camera interface, on-board memory and several peripheral devices such as wifi, bluetooth radios. The Processor is basically an integration of CPU and motherboard chipset. The baseband processor is what controls the cellular wireless communication.

The fundamental difference between a desktop processor and a mobile processor is the amount of power consumption (we do not want the battery to die off in a couple of minutes) and the heat sink (the heat generated should not be large). A typical Core 2 Duo consumes 65W and requires an active cooling system to keep it from overheating. Even Intel’s Atom Chip consumes 4W while entire cellphones must fit in sub-1W power budgets.

The biggest name in mobile processor architecture today is the ARM that dominates high-end mobile phones and embedded device like network routers. In its lowest power state, an Atom processor consumes 100mW while the typical range of an ARM processor is 1mW. Now what is important to know is the fundamental difference between ARM and Intel which is that ARM  creates Instruction Sets – any CPU running them will be able to run ARM-compatible code. It also creates reference designs for processors that fit their instruction sets, which allow companies to easily produce their own chipset around ARM’s core designs. Some companies like NVidia, Samsung and Texas Instruments simply license and adopt the ARM CPU reference design whereas others like Qualcomm and Marvell, license only the instruction set and create their own processors to fit them.

There are basically two versions of ARM reference design going on today: ARMv6 (which is found in lower end smartphones which use ARM 11 chips) and ARMv7 (which is more prevalent in today’s high end smartphones). Smartphone chipsets have different forms of integration. For example, one of NVidia’s Tegra chipset is that its application processor has several small specialized processors built into it, each meant for particular tasks. Many chipsets are made this way but Tegra has more dedicated co-processors than most. The advantage of this is that the general purpose core can be freed up to handle user tasks and also it can power off those parts of the processor that arent being used. For example, if ZuneHD is playing music with its screen off, why power anything but the audio processor and things related to that. Tegra 2 solves much of first-gen chips problems by having a dual-core ARM Cortex A9 CPU which is 4 times faster than Tegra 1 for general processing. GPU processing is also twice as faster while the power consumption remains the same. ARMS CEO Warren East described it thus in an interview, “It’s like having a car with a fixed-size fuel tank and you want to drive 100 more miles. You’ve got to make the engine more efficient. That’s what we do for a living.”

Now Intel is beginning to compete with ARM (Over 2 billion ARMS chips are shipped every year) by betting that a shrunken Atom will give its power consumption comparable to ARM’s offerings yet greater processing power and most significantly, the x86 architecture (compatible with desktops and PC OS’es like Win XP/ 7). Although it is too early to say, Warren East is highly confident of his company saying that Intel has put in major flaws in its design which will create problems for them in the future. Thus an imminent war is brewing and it will begin in the second half of this year when the Lenovo’s K800 smartphone will be the first Atom-based phone. Intel lost out a great opportunity when one of its biggest ally, Microsoft decided to ship its new OS with ARM processors. We will have to wait and see how the story rolls out though.

Mobile CPU Overview (as taken from

An overview of most of the major mobile processor families on the market today (chips that have not yet shipped in production are italicized):

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