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 MIDs . The Atom Z series is code-named Silverthorne and the Atom N series is code-named Diamondville. As of June 2009, the most used chips in the Netbook retail market are Z520, Z530, and N270

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

Architecture

Intel Atom can execute up to two instructions per cycle. The performance of a single core Atom is equal to around half that offered by an equivalent Celeron . 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, [ 12 ] compared to 7400 MIPS and 3.9 GFLOPS for the similarly clocked (1.73 GHz) Pentium M 740. [ 13 ] Atom implements the x86 ( IA-32 ) instruction set; x86-64 is so far only activated for the Atom 230 and 330 desktop models. N and Z series Atom models cannot run x86-64 code. [ 14 ] Like many other x86 microprocessors, it translates x86-instructions into simpler internal operations ( micro-ops ) prior to execution. The majority of instructions produce one micro-op when translated, with around 4% 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 Atom, internal µ-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 µ-ops used in previous designs. [ 15 ] This enables relatively good performance with only two integer ALUs, and without any instruction reordering, speculative execution, or register renaming. Atom therefore represents a partial revival of the principles used in earlier Intel designs such as Intel P5 and the i486 , with the sole purpose of enhancing the performance per watt ratio. However, Hyper-Threading is implemented as an easy (i.e. low power) way to employ both pipelines efficiently by avoiding the typical single thread dependencies. [ 15 ]

Atom Z series

On March 2, 2008, Intel announced a new single-core processor (code-named Silverthorne ) to be used in ultra-mobile PCs / Mobile Internet Devices (MIDs) which will supersede Intel A100 . The processor is a 47 million transistor, 25 mm 2 , 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 Intel A110 , but should outperform it on applications that can leverage simultaneous multithreading , SSE3 , and Intel 64 extensions. [ 16 ] 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 [ 17 ] 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. [ 18 ] [ 19 ]

Atom N series

On March 2, 2008, Intel announced a low-cost mobile processor (code-named Diamondville ) to be used in the Classmate PC Netbook . It is used in Intel's low-cost Mini-ITX motherboards (code-named "Little Falls") and in a number of netbooks . [ 20 ] [ 21 ] [ 22 ] [ 23 ] It will supersede Conroe L as the N270 (2.5 W TDP ) for netbooks and as 230 (4 W TDP ) for nettops , each running at 1.6 GHz core speed (both N270 & 230 are single core) [ 24 ] [ 25 ] with a 533 MHz FSB speed. An N280 with a 1.66 GHz clockspeed and a 667 MHz FSB has since appeared. Both the Atom N270 and Atom N280 are single core processors which support Intel Hyper-Threading Technology.

Atom 300 series

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).

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

Power requirements

While 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 chip itself commonly used in netbooks has a maximum TDP of 2.5 W, the Intel Atom platform with the 945GSE Express chipset has a specified maximum TDP of 11.8 W, with the processor only making up a relatively small portion of the total power. 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. [ 26 ] [ 27 ] [ 28 ] [ 29 ] Intel also provides the Intel System Controller Hub US15W 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). [ 30 ]

Initially, all Atom motherboards on the consumer market featured the Intel 945G 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.