|
||||
Intel’s new Atom processor was designed from the ground up to deliver x86 performance at incredibly low power: less than one watt when running “typical” mobile applications. Everyone at Intel, from CEO Paul Otellini on down, has been touting Atom for applications ranging from smartphones and consumer electronics to industrial equipment and low-cost PCs. A closer look, however, reveals that Atom cannot possibly satisfy the needs of all these markets. Like other Intel processors, it is best suited to PCs and PC-like applications. Although Atom will be used in some consumer devices, its shortcomings will keep it out of high-volume designs, at least initially. Just the Facts Atom is in production at speed grades from 800MHz to 1.86GHz. The two most popular versions, which are both supported for long-life embedded designs, are 1.1GHz ($45) and 1.6GHz ($95). The price includes both the processor and its associated system-logic chip. When Intel quotes an “average” CPU power of 220mW, it assumes the CPU is active only 10% of the time. Furthermore, this figure does not include the power used by the system-logic chip. Together, the two chips burn about 2.5W when running typical code and about 1.0W when idle. Thermal design power (TDP) for the chip set is 4.3W. Although Atom achieves impressive clock speeds, its performance is lower than that of other Intel processors. Intel estimates that the 1.6GHz Atom delivers performance similar to a Pentium-M processor at half that speed, due to Atom’s simpler CPU architecture and smaller cache. To help compensate, Atom offers a new multithreading mode that can improve performance by about 30% for software written for dual threads. Mobile Internet Devices Intel touts Atom as competition for ARM, but even the slowest version costs more than twice as much as the ARM-based application processors typically used in smartphones. Furthermore, Atom burns far more power, particularly in idle mode, and would quickly drain the battery of any smartphone. It also requires more than four times the board area of ARM processors. Atom’s primary advantage is performance: it is at least twice as fast as any ARM11 or ARM Cortex product available today. But smartphones don’t need that much performance. The iPhone, for example, is considered one of the most advanced smartphones available, yet it relies on a 333MHz ARM11 CPU. Atom is better suited to bigger devices with larger batteries, such as devices with a screen size of 100mm to 150mm. Some GPS devices and a few media players fit into this category. Intel must convince these device makers to pay a premium for a faster CPU. In the GPS example, Atom could calculate routes more quickly than an ARM processor. The GPS maker, however, would have to port its software to Intel’s architecture. Intel has postulated a new category, the mobile Internet device (MID), that is larger than a smartphone but focuses on Internet access. We are skeptical that this category will succeed, because consumers generally prefer pocket-sized devices. MIDs will be more popular in work areas, such as hospitals or warehouses. Embedded Opportunities With its sub-5W TDP, Atom can be used in line-powered equipment, such as in business or consumer networking. But Atom lacks ECC protection, a reliability feature required in most business networking equipment. Intel offers ECC mainly in its server products. The Atom chip set also lacks an encryption engine, a RAID engine, SATA (hard drive) interfaces, Ethernet MACs, and a Flash memory controller. These features are common in integrated ARM and MIPS processors but must be added externally in Atom designs, increasing cost and board area. In high-volume designs such as residential gateways, the processor may integrate additional functions, such as DSL or Wi-Fi. Atom, of course, lacks these capabilities as well. The Intel chip is best for low-volume consumer equipment, such as a home media server, for which reducing design time is more important than cost or board space. On the plus side, Atom offers impressive performance per watt. While many embedded competitors still use 90nm, Intel builds Atom in a 45nm process, greatly reducing power. Unlike RISC processors, the x86 chip is fully PC compatible and can take advantage of the PC hardware and software infrastructure. Atom will be successful is embedded markets where x86 is already well established: kiosks, point-of-sale terminals, and industrial applications. The second-generation Atom, which promises further reductions in power and board area, will be needed for Intel to gain any significant ground in handheld devices.
Originally published in Nikkei Electronics Asia, June 2008
|
