Intel Atom

This article is about the line of processors. For system on chips designed for smartphones and tablets, see Atom (system on chip).

Intel Atom

Intel Atom Z520 compared to a 1 Eurocent coin. It is 182 mm2.
General information
Launched	2008–present
Common manufacturer(s)	Intel
Performance
Max. CPU clock rate	600 MHz to 2.13 GHz
FSB speeds	400 MHz to 667 MHz
Architecture and classification
Technology node	45 nm to 32 nm
Instruction set	MMX, SSE, SSE2, SSE3, SSSE3, IA-32, x86-64 (not for the N2xx and Z5xx series)
Physical specifications
Cores	1, 2
Package(s)	441-ball µFCBGA
Products, models, variants
Core name(s)	Silverthorne Diamondville Pineview Lincroft

Intel Atom is the brand name for a line of ultra-low-voltage IA-32 and x86-64 CPUs (or microprocessors) from Intel, originally designed in 45 nm CMOS with subsequent models, codenamed Cedar, using a 32 nm process. Atom is mainly used in netbooks, nettops, embedded applications ranging from health care to advanced robotics, and mobile internet devices (MIDs).

Atom processors are based on the Bonnell microarchitecture. On 21 December 2009, Intel announced the Pine Trail platform, including new Atom processor code-named Pineview (Atom N450), with total kit power consumption down 20%. On 28 December 2011, Intel updated the Atom line with the Cedar processors.

History

Intel Atom is a direct successor of the Intel A100 and A110 low-power microprocessors (code-named Stealey), which were built on a 90 nm process, had 512 KB L2 cache and ran at 600 MHz/800 MHz with 3W TDP (Thermal Design Power). Prior to the Silverthorne announcement, outside sources had speculated that Atom would compete with AMD's Geode system-on-a-chip processors, used by the One Laptop per Child (OLPC) project, and other cost and power sensitive applications for x86 processors. However, Intel revealed on 15 October 2007 that it was developing another new mobile processor, codenamed Diamondville, for OLPC-type devices.

"Atom" was the name under which Silverthorne would be sold, while the supporting chipset formerly code-named Menlow was called Centrino Atom.

At Spring Intel Developer Forum (IDF) 2008 in Shanghai, Intel officially announced that Silverthorne and Diamondville are based on the same microarchitecture. Silverthorne would be called the Atom Z5xx series and Diamondville would be called the Atom N2xx series. The more expensive lower-power Silverthorne parts will be used in Intel Mobile Internet Devices (MIDs) whereas Diamondville will be used in low-cost desktop and notebooks. Several Mini-ITX motherboard samples have also been revealed. Intel and Lenovo also jointly announced an Atom powered MID called the IdeaPad U8.

In April 2008, a MID development kit was announced by Sophia Systems and the first board called CoreExpress-ECO was revealed by a German company LiPPERT Embedded Computers, GmbH. Intel offers Atom based motherboards.

Intel Atom processor family
MID / Ultra-Mobile PC / Lifestyle PC
Logo	Code-name	Series	Core	On-Die GPU	GPU Speed	TDP	HT	Intel 64	Intel VT-x	Release date
	Silverthorne	Atom Z5xx	single (45 nm)	No	n/a	0.65~2 W	No	No	No	April 2008
						2~2.4 W	Yes		Yes
	Lincroft	Atom Z6xx	single (45 nm)	Yes	400 MHz	1.3~3 W	Yes	No	Yes	May 2010
Classmate PC / Netbook / Nettop / Lifestyle PC
Logo	Code-name	Series	Core	On-Die GPU	GPU Speed	TDP	HT	Intel 64	Intel VT-x	Release date
	Diamondville	Atom N2xx	single (45 nm)	No	n/a	2.5 W	Yes	No	No	June 2008
		Atom 2xx				4 W		Yes
		Atom 3xx	dual (45 nm)			8 W				September 2008
	Pineview	Atom N4xx	single (45 nm)	Yes	200 MHz	6.5 W	Yes	Yes	No	January 2010
		Atom D4xx			400 MHz	10 W
		Atom N5xx	dual (45 nm)		200 MHz	8.5 W
		Atom D5xx			400 MHz	13 W
	Cedarview	Atom D2500	dual (32 nm)	Yes	400 MHz	10 W	No	Yes	No	November 2011
		Atom D2700			640 MHz		Yes
		Atom N2600			400 MHz	3.5 W				December 2011
		Atom N2800			640 MHz	6.5 W
List of Intel Atom microprocessors

Availability

Atom processors became available to system manufacturers in 2008. Because they are soldered, like northbridges and southbridges, onto a mainboard, Atom processors are not available to home users or system builders as separate processors, although they may be obtained preinstalled on some ITX motherboards. The Diamondville and Pineview Atom is used in the HP Mini Series, aigo MID Asus N10, Lenovo IdeaPad S10, Acer Aspire One & Packard Bell's "dot" (ZG5), recent ASUS Eee PC systems, Sony VAIO M-series, AMtek Elego, Dell Inspiron Mini Series, Gigabyte M912, LG X Series, Samsung NC10, Sylvania g Netbook Meso, Toshiba NB series (100, 200, 205, 255, 300, 500, 505), MSI Wind PC netbooks, RedFox Wizbook 1020i, Sony Vaio X Series, Zenith Z-Book, a range of Aleutia desktops,and the Archos 10

Performance

The performance of a single core Atom is about half that of a Pentium M of the same clock rate. For example, the Atom N270 (1.60 GHz) found in many netbooks such as the Eee PC can deliver around 3300 MIPS and 2.1 GFLOPS in standard benchmarks, compared to 7400 MIPS and 3.9 GFLOPS for the similarly clocked (1.73 GHz) Pentium M 740.

The Pineview platform has proven to be only slightly faster than the previous Diamondville platform. This is because the Pineview platform uses the same Bonnell execution core as Diamondville and is connected to the memory controller via the FSB, hence memory latency and performance in CPU-intensive applications are minimally improved.

Instruction set architecture

Atom implements the x86 (IA-32) instruction set; x86-64 is so far only activated for the desktop Diamondville and desktop and mobile Pineview cores. The Atom N2xx and Z5xx series Atom models cannot run x86-64 code.

Bonnell microarchitecture

Main article: Bonnell (microarchitecture)

Intel Atom processors are based on the Bonnell microarchitecture, which can execute up to two instructions per cycle. Like many other x86 microprocessors, it translates x86-instructions (CISC instructions) into simpler internal operations (sometimes referred to as micro-ops, i.e., effectively RISC style instructions) prior to execution. The majority of instructions produce one micro-op when translated, with around 4% of instructions used in typical programs producing multiple micro-ops. The number of instructions that produce more than one micro-op is significantly fewer than the P6 and NetBurst microarchitectures. In the Bonnell microarchitecture, internal micro-ops can contain both a memory load and a memory store in connection with an ALU operation, thus being more similar to the x86 level and more powerful than the micro-ops used in previous designs. This enables relatively good performance with only two integer ALUs, and without any instruction reordering, speculative execution, or register renaming. The Bonnell microarchitecture therefore represents a partial revival of the principles used in earlier Intel designs such as P5 and the i486, with the sole purpose of enhancing the performance per watt ratio. However, Hyper-Threading is implemented in an easy (i.e., low power) way to employ the whole pipeline efficiently by avoiding the typical single thread dependencies.

Future CPU releases

According to Intel spokeswoman Suzy Ramirez, speaking to CNET in June 2011, Intel has the following release plans:

• 2012: ValleyView (32 nm) Current CedarView but with Ivy Bridge graphics
• 2013: Silvermont (22 nm) DDR3-1333
• 2014: Airmont (14 nm)

Collaborations

In March 2009, Intel announced that it would be collaborating with TSMC for the production of the Atom processors. The deal was put on hold due to lack of demand in 2010.

On 13 September 2011 Intel and Google held a joint announcement of a partnership to provide support in Google's Android operating system for Intel processors (beginning with the Atom). This would allow Intel to supply chips for the growing smartphone and tablet market.

Competition

The direct competitor of the Intel Atom is the AMD Fusion C- and E-series. The C-series (C-30: single core, C-50/C-60: dual cores) has a TDP (9W) similar to the Atom, while the higher clocked E-series (E-240: single core, E-350/E-450: dual core) has a TDP of 18 Watts that corresponds more to an Atom including a dedicated GPU (e.g. ION2, ATI 5430). The processors include a single or dual core 64-bit CPU with out-of-order execution, DDR3 memory controller and an 80-core Radeon GPU. The performance of the E-series outperforms Intel Atom in most tests - up to 326.5% better game performance according to "Tom's Hardware.com".

Embedded processors based on the ARM version 7 instruction set architecture (such as Nvidia's Tegra 3 series, TI's OMAP 4 series and Freescale's i.MX51 based on the Cortex-A8 core, or the Qualcomm Snapdragon and Marvell Armada 500/600 based on custom ARMv7 implementations) offer similar performance to the low end Atom chipsets but at roughly one quarter the power consumption, and (like most ARM systems) as a single integrated system on a chip, rather than a two chip solution like the current Atom line. Although the second-generation Atom codenamed "Pineview" should greatly increase its competitiveness in performance/watt, ARM plans to counter the threat with the multi-core capable Cortex-A9 core as used in Nvidia's Tegra 2/3, TI's OMAP 4 series, and Qualcomm's next-generation Snapdragon series, among others.

The Nano and Nano Dual-Core series from VIA is slightly above the average thermal envelope of the Atom, but offers hardware AES support, random number generators, and out-of-order execution. Performance comparisons of the Intel Atom against the Via Nano indicate that a single core Intel Atom is outperformed by the Via Nano which is in turn outperformed by a dual core Intel Atom 330 in tests where the second core is used. The Core 2 Duo SU7300 outperforms the dual-core Nano.

The Xcore86 (also known as the PMX 1000) is x586 based System on Chip (SoC) that offers a below average thermal envelope compared to the Atom.

Kenton Williston of EE Times said that while Atom will not displace ARM from its current markets, the ability to apply the PC architecture into smaller, cheaper and lower power form factors will open up new markets for Intel.

See also

• List of Intel Atom microprocessors
• Intel Atom (system on chip)

References

• "Intel cranks 45nm ultramobile CPU". EE Times. 18 April 2007. Retrieved 28 October 2007.
• "Intel reaches back in time for its ultralow power chips". 28 January 2008. Retrieved 29 January 2008.
• "New Intel Centrino Atom Processor Technology Ushers in 'Best Internet Experience in Your Pocket'". 2 April 2008.
• "Intel's Atom Architecture: The Journey Begins". 2 April 2008.
• "The Battle of Low-Power Processors: Best Choice for a Nettop". 27 September 2008.
• linuxdevices.com - Intel announces first Atom chips
• hardwaresecrets.com - Inside Atom Architecture
• computermonger.com - Intel Atom N280 vs N270 Benchmarked
• LinuxTECH.NET - Intel Pineview Atom based Motherboards Complete Overview

External links

• Intel - Intel Atom Processor Overview
• Intel Atom Processor
• Intel - Intel Atom Processor Family