Intel Atom

Intel Atom

Intel Atom Z520 compared to a 1 Eurocent coin. It is about 1.5cm square.
Produced	2008–present
Common manufacturer(s)	Intel
Max. CPU clock rate	800 MHz to 2.13 GHz
FSB speeds	400 MHz to 667 MHz
Min. feature size	45 nm
Instruction set	MMX, SSE, SSE2, SSE3, x86, x86-64 (not for the N2xx and Z5xx series)
Cores	1, 2
Package(s)	441-ball µFCBGA
Core name(s)	Silverthorne Diamondville Pineview Lincroft

Intel Atom is the brand name for a line of ultra-low-voltage x86 and x86-64 CPUs (or microprocessors) from Intel, designed in 45 nm CMOS and used mainly in netbooks, nettops, and Mobile Internet devices (MIDs). On December 21, 2009, Intel announced the next generation of Atom processors, including the N450, with total kit power consumption down 40%.^[1]

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 run 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 project, and other cost- and power-sensitive applications for x86 processors. However, Intel revealed on October 15, 2007 that it was developing another new mobile processor, codenamed Diamondville, for OLPC-type devices.^[2]

"Atom" was the name under which Silverthorne would be sold, while the supporting chipset formerly code-named Menlow was called Centrino Atom.^[3] Intel's initial Atom press release only briefly discussed "Diamondville" and implied that it too would be named "Atom",^[4] strengthening speculation that Diamondville is simply a lower-cost, higher-yielding version of Silverthorne with slightly higher TDPs at slightly lower clock speeds.^[5]

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.^[6] Intel and Lenovo also jointly announced an Atom powered MID called the IdeaPad U8.^[7] The IdeaPad U8 weighs 280 g and has a 4.8 in (12 cm) touchscreen providing better portability than a netbook PC and easier Internet viewing than a mobile phone or PDA.

In April 2008, a MID development kit was announced by Sophia Systems^[8] and the first board called CoreExpress-ECO was revealed by a German company LiPPERT Embedded Computers, GmbH.^[9][10] Intel offers Atom based motherboards.^[11][12]

Intel Atom processor family
Logo	Code-name	Series	Core	On-Die GPU	TDP	HT	Intel 64	Intel VT-x	Release date
MID / Ultra-Mobile PC
	Silverthorne	Atom Z5xx	single (45 nm)	No	0.65~2 W	No	No	No	April 2008
					2~2.4 W	Yes		Yes
	Lincroft	Atom Z6xx		Yes	? W				May 2010
Classmate PC / Netbook / Nettop
	Diamondville	Atom N2xx	single (45 nm)	No	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	6.5 W				January 2010
		Atom D4xx			10 W
		Atom D5xx	dual (45 nm)		13 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 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, AMtek Elego, Dell Inspiron Mini Series, Gigabyte M912, LG X Series, Samsung NC10, Sylvania g Netbook Meso, Toshiba NB series (100, 200, 205), MSI Wind PC netbooks, RedFox Wizbook 1020i, 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 found in many netbooks such as the Eee PC can deliver around 3300 MIPS and 2.1 GFLOPS in standard benchmarks,^[13] compared to 7400 MIPS and 3.9 GFLOPS for the similarly clocked (1.73 GHz) Pentium M 740.^[14]

The Pineview platform has proven to be not much faster than the previous Diamondville platform. This is because the Pineview platform uses the same Bonnell execution core as Diamondville and is still connected to the memory controller via FSB. This is why memory latency and performance in CPU-intensive applications is barely improved.^[15]

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.^[16]

Bonnell microachitecture

Intel Atom processors are based on the Bonnell microarchitecture^[17][18] 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.^[19] 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 both pipelines efficiently by avoiding the typical single thread dependencies.^[19]

First generation cores

Silverthorne microprocessor

On March 2, 2008, Intel announced a new single-core Atom Z5xx series processor (code-named Silverthorne) to be used in ultra-mobile PCs/mobile Internet devices (MIDs) which will supersede Stealey (A100 and A110). The processor is a 47 million transistor, 25 mm², sub-3 W IA processor which allows ~2500 chips to fit on a single 300 mm diameter wafer, allowing for extremely economical production.

An Atom Z500 processor's dual-thread performance is equivalent to its predecessor Stealey, but should outperform it on applications that can leverage simultaneous multithreading and SSE3.^[20] They run from 0.8 to 2.0 GHz and have between 0.65 and 2.4 W TDP rating respectively that can dip down to 0.01 W^[21] when idle. It features a 2-issue simultaneous multithreading, 16 stage in-order pipeline with 32 KB instruction L1 and 24 KB data L1 caches, integer and floating point execution units, x86 front end, a 512 KB L2 cache and data transferred at 533 MHz on the front-side bus. The design is manufactured in 9M 45 nm high-k metal-gate CMOS and housed in a 441-ball µFCBGA package.^[22][23]

Diamondville microprocessor

The Intel Atom N270

On March 2, 2008, Intel announced lower-power variants of the Diamondville CPU deemed Atom N2xx series. It had previously been intended for nettops, to be used in the Classmate PC netbook.^{[24][25][26][27]} Like their predecessors, these are single-core parts with HyperThreading.

The N270 has 2.5 W TDP, running at 1.6 GHz^[28] with a 533 MHz FSB. The N280 has a 1.66 GHz clockspeed and a 667 MHz FSB.^[29]

On September 22, 2008, Intel announced a new dual-core processor (unofficially code-named Dual Diamondville) branded Atom 330 of the Atom 300 series to be used in desktop computers. It runs at a 1.6 GHz clock speed and has an FSB running at 533 MHz. The processor has an 8 W TDP rating. Its dual core comprises two Diamondville dies next to each other on a single package (substrate). Atom 330 supports 64 bit instructions.

During 2009, Nvidia used the Atom 300 and their GeForce 9400M chipset on a mini-ITX form factor motherboard for their Ion platform.

Second generation cores

Pineview microprocessor

On December 21, 2009, Intel announced the N450, D510 and D410 with integrated graphics.^[1] Total kit power goes from 11.8 W to 7 W with the new processor and chipset, a 40% improvement.^[30][31] Intel GMA 3150, a 45 nm shrink of the GMA 3100 with no HD capabilities, is included as the on-die GPU. Netbooks using this new processor were expected to be publicly shown at CES on January 4, 2010, and to be released for sale on January 11, 2010.^[32][33] The major new feature includes longer battery life, with 6 cell systems reporting 10 or more hours of battery life.^[34][35][36] The current generation of the Atom is codenamed "Pineview" which is used in the "Pine Trail" platform. Intel's current netbook platform (codenamed Pine Trail-M) utilizes an Atom processor (codenamed Pineview-M) and Platform Controller Hub (codenamed Tiger Point). The graphics and memory controller have moved into the processor, which is paired with the Tiger Point PCH. This creates a more power efficient 2-chip platform rather than the 3-chip one used with previous-generation Atom chipsets.^[37]

On 1 March, 2010 Intel officially announced the introduction of the N470 processor,^[38][39] running at 1.83 GHz with a 667 MHz FSB and a Max TDP of 6.5 W.^[16]

The new Atom N4xx chips became available on January 11, 2010.^[40] It is used in netbook/nettop systems, and features an integrated single-channel DDR2 memory controller and an integrated graphics core. It features hyper-threading and is still manufactured on a 45 nm^[41] process. The new design uses half the power of the older "Menlow" platform. This reduced overall power consumption and size makes the platform more desirable for use in smartphones and other mobile internet devices.

LinuxTECH.NET^[42] has put together an overview of all announced/released "Pine Trail" platform motherboards.

On December 23, 2009, MSI introduced a new series of netbooks to be released in January 2010, the Wind U130 and U135, which are among the first netbooks to incorporate the new "Pine Trail" platform. Other companies, like ASUS and Dell have since also introduced netbooks based on the Pineview-M chip N4xx.

The D4xx and D5xx series support the x86-64 bit instruction set and DDR2-800. It is rated for embedded use. The series has an integrated graphics processor built directly into the CPU to help improve performance. The models are targeted at nettops and low end desktops. They do not support speedstep.

The Atom D510 processor features dual core running at 1.66 GHz, with 1 MB of L2 cache.^[43] The Atom D410 processor features a single core running at 1.66 GHz, with 512 KB of L2 cache.^[44] Power requirements are rated at 13 watts^[43] for the D510 and 10 watts^[44] for the D410.

Lincroft microprocessor

Power requirements

The relatively power-efficient Atom CPU is often used with a cheaper, more power consuming chipset like the Intel 945G

Although the Atom processor itself is relatively power efficient for an x86 microprocessor, many chipsets commonly used with it dissipate significantly more power. For example, while the N270 CPU commonly used in netbooks has a net maximum TDP of 2.5 W, an Intel Atom platform that uses the 945GSE Express chipset has a specified maximum TDP of 11.8 W, with the processor using a relatively small portion of the total power consumed. Individual figures are 2.5 W for the N270 processor, 6 W for the 945GSE chipset and 3.3 W for the 82801GBM I/O controller.^{[45][46][47][48]} Intel also provides a US15W System Controller Hub based chipset with a combined TDP of less than 5 W together with the Atom processor Z5xx (Silverthorne) series, to be used in ultra-mobile PCs/Mobile Internet Devices (MIDs).^[49]

Initially, all Atom motherboards on the consumer market featured the Intel 945GC chipset, which uses 22 watts alone. As of early 2009, only a few manufacturers are offering lower power 945GSE-based motherboards to end users, paired with the Atom N270 or N280 CPU, while Sony VAIO P pioneers the use of the low power US15W chipset with Z5xx series processors.

Future

In the second half of 2010, Intel will release new versions of Pineview Atom chips that will support DDR3 memory.^[50]

In the second half of 2011, Intel will release a new Atom platform for netbooks and nettops codenamed "Cedar Trail", which will be fabricated on the 32 nm technology. Development of the new chip and platform will begin in late 2010. Intel claims that the chip will boast higher clock speeds and double performance as compared to "Pine Trail", although details are scarce. The code name of the platform is Cedar View and is rumored to have double the graphical power as the GMA 3150 in the current Pineview platform.^[51]

Collaboration with TSMC

In March 2009, Intel announced that they will be collaborating with TSMC for the production of the Atom processors.^[52]

Competition

The direct competitor from AMD is the Athlon Neo. It has significantly higher TDP (15W) than Atom. With 27 mm × 27 mm in size and 2.5 mm in thickness, the Athlon Neo processors utilize a new package called "ASB1", essentially a BGA package, for smaller footprint to allow smaller designs for notebooks and lowering the cost. The clock of the processors is significantly lower than desktop and other mobile counterparts to reach a low TDP, at 15 W maximum for a single core x86 CPU. The Athlon Neo processors are equipped with 512 KB of L2 cache and HyperTransport 1.0 running at 800 MHz frequency.

Embedded processors based on the ARM version 7 instruction set architecture (such as TI's OMAP 3 series and Freescale's i.MX51 based on the Cortex-A8 processor, 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 next-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 processor as used in Nvidia's Tegra 2, T.I.'s OMAP 4 series, and Qualcomm's next-generation Snapdragon series, among others.

The Nano 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.^{[53][54][55][56][57][58][59]}

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.^[60]

See also

• List of Intel Atom microprocessors

References

Press

• "Intel cranks 45nm ultramobile CPU". EE Times. 2007-04-18. http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=199100535. Retrieved 2007-10-28. 
• "Intel reaches back in time for its ultralow power chips". 2008-01-28. http://www.news.com/8301-10784_3-9859616-7.html. Retrieved 2008-01-29. 
• "New Intel Centrino Atom Processor Technology Ushers in 'Best Internet Experience in Your Pocket'". 2008-04-02. http://www.intel.com/pressroom/archive/releases/20080401comp.htm. 
• Intel to launch 3 new Atom CPUs
• "Intel's Atom Architecture: The Journey Begins". 2008-04-02. http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3276. 
• "The Battle of Low-Power Processors: Best Choice for a Nettop". 2008-09-27. http://www.xbitlabs.com/articles/cpu/display/intelatom-vianano.html. 
• linuxdevices.com - Intel announces first Atom chips
• hardwaresecrets.com - Inside Atom Architecture
• computermonger.com - Intel Atom N280 vs N270 Benchmarked

External links

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