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Первый в истории компьютер на нанотрубках использует подмножество архитектуры MIPS [Sep. 28th, 2013|04:34 am]
Yuri Panchul
В Стенфорде сделали первый в истории компьютер на нанотрубках. Причем в качестве архитектуры он использует подмножество архитектуры MIPS! По этому поводу вышла статья в MIT Technology Review. Единственная проблема: так как по количеству транзисторов компьютер очень небольшой, то статья стала сравнивать его с первым микропроцессором Intel 4004 и ввела некоторых комментаторов в сворачивание мозгов заблуждение. Вообще архитектура MIPS не имеет вообще ничего общего с Intel 4004. Пришлось разъяснять.


The First Carbon Nanotube Computer
A carbon nanotube computer processor is comparable to a chip from the early 1970s, and may be the first step beyond silicon electronics.

By Katherine Bourzac on September 25, 2013


For progress in computer power to continue, new materials will be needed for the most basic components.

For the first time, researchers have built a computer whose central processor is based entirely on carbon nanotubes, a form of carbon with remarkable material and electronic properties. The computer is slow and simple, but its creators, a group of Stanford University engineers, say it shows that carbon nanotube electronics are a viable potential replacement for silicon when it reaches its limits in ever-smaller electronic circuits.

The carbon nanotube processor is comparable in capabilities to the Intel 4004, that company’s first microprocessor, which was released in 1971, says Subhasish Mitra, an electrical engineer at Stanford and one of the project’s co-leaders. The computer, described today in the journal Nature, runs a simple software instruction set called MIPS. It can switch between multiple tasks (counting and sorting numbers) and keep track of them, and it can fetch data from and send it back to an external memory.

The nanotube processor is made up of 142 transistors, each of which contains carbon nanotubes that are about 10 to 200 nanometer long. The Stanford group says it has made six versions of carbon nanotube computers, including one that can be connected to external hardware—a numerical keypad that can be used to input numbers for addition.

Aaron Franklin, a researcher at the IBM Watson Research Center in Yorktown Heights, New York, says the comparison with the 4004 and other early silicon processors is apt. “This is a terrific demonstration for people in the electronics community who have doubted carbon nanotubes,” he says.

Franklin’s group has demonstrated that individual carbon nanotube transistors—smaller than 10 nanometers—are faster and more energy efficient than those made of any other material, including silicon. Theoretical work has also suggested that a carbon nanotube computer would be an order of magnitude more energy efficient than the best silicon computers. And the nanomaterial’s ability to dissipate heat suggests that carbon nanotube computers might run blisteringly fast without heating up—a problem that sets speed limits on the silicon processors in today’s computers.

Still, some people doubt that carbon nanotubes will replace silicon. Working with carbon nanotubes is a big challenge. They are typically grown in a way that leaves them in a tangled mess, and about a third of the tubes are metallic, rather than semiconducting, which causes short-circuits.

Over the past several years, Mitra has collaborated with Stanford electrical engineer Philip Wong, who has developed ways to sidestep some of the materials challenges that have prevented the creation of complex circuits from carbon nanotubes. Wong developed a method for growing mostly very straight nanotubes on quartz, then transferring them over to a silicon substrate to make the transistors. The Stanford group also covers up the active areas of the transistors with a protective coating, then etches away any exposed nanotubes that have gone astray.

Wong and Mitra also apply a voltage to turn all of the semiconducting nanotubes on a chip to “off.” Then they pulse a large current through the chip; the metallic ones heat up, oxidize, and disintegrate. All of these nanotube-specific fixes—and the rest of the manufacturing process—can be done on the standard equipment that’s used to make today’s silicon chips. In that sense, the process is scalable.

Late last month at Hot Chips, an engineering design conference hosted, coincidentally, at Stanford, the director of the Microsystems Technology Office at DARPA made a stir by discussing the end of silicon electronics. In a keynote, Robert Colwell, former chief architect at Intel, predicted that by as early as 2020, the computing industry will no longer be able to keep making performance and cost improvements by doubling the density of silicon transistors on chips every 18 to 24 months—a feat dubbed Moore’s Law after the Intel cofounder Gordon Moore, who first observed the trend.

Mitra and Wong hope their computer shows that carbon nanotubes may be a serious answer to the question of what comes next. So far no emerging technologies come close to touching silicon. Of all the emerging materials and new ideas held up as possible saviors—nanowires, spintronics, graphene, biological computers—no one has made a central processing unit based on any of them, says Mitra. In that context, catching up to silicon’s performance circa 1970, though it leaves a lot of work to be done, is exciting.

Victor Zhirnov, a specialist in nanoelectronics at the Semiconductor Research Corporation in Durham, North Carolina, is much more cautiously optimistic. The nanotube processor has 10 million times fewer transistors on it than today’s typical microprocessors, runs much more slowly, and operates at five times the voltage, meaning it uses about 25 times as much power, he notes.

Some of the nanotube computer’s sluggishness is due to the conditions under which it was built—in an academic lab using what the Stanford group had access to, not an industry-standard factory. The processor is connected to an external hard drive, which serves as the memory, through a large bundle of electrical wires, each of which connects to a large metal pin on top of the nanotube processor. Each of the pins in turn connects to a device on the chip. This messy packaging means the data has to travel longer distances, which cuts into the efficiency of the computer.

With the tools at hand, the Stanford group also can’t make transistors smaller than about one micrometer—compare that with Intel’s announcement earlier this month that its next line of products will be built on 14-nanometer technology. If, however, the group were to go into a state-of-the-art fab, its manufacturing yields would improve enough to be able to make computers with thousands of smaller transistors, and the computer could run faster.

To reach the superb level of performance theoretically offered by nanotubes, researchers will have to learn how to build complex integrated circuits made up of pristine single nanotube transitors. Franklin says device and materials experts like his group at IBM need to start working in closer collaboration with circuit designers like those at Stanford to make real progress.

“We are well aware that silicon is running out of steam, and within 10 years it’s coming to its end,” says Zhirnov. “If carbon nanotubes are going to become practical, it has to happen quickly.”

Как всегда в таких статьях, в комменты прибежал болельщик за ARM и начал агитировать за любимую архитектуру, не понимая, что 1) ARM и MIPS - обе RISC-архитектуры, возникшие примерно в одно и то же время; 2) 4004 не имеет никакого отношения к MIPS; 3) представлять эволюцию компьютерных архитектур как "4004 -> 8088 -> ARM" - это такой же бред такая же ложная картина мира, как представлять эволюционную цепочку "улитка -> осминог -> дельфин":

sanman 2 days ago
How long until an 8088? That will bring us from the 70s to the 80s.
However, going after an ARM type of design might bypass all of that.

panchul 34 minutes ago
@sanman You are obviously got confused by the reference to 4004. 4004 is used in this article to compare 1) the relative complexity of the chip 2) the fact it is first of its kind.

This nanotube chip is using a subset of MIPS architecture, not 4004 architecture. MIPS architecture has nothing to do with 4004. In fact MIPS and ARM are siblings - both are RISC architectures that emerged at the same time - early 1980s.

Both MIPS and ARM are used in modern gadgets like digital TVs, routers etc. ARM is more popular because of its use use in cell phones. But MIPS has certain advantages over ARM (hardware multithreading in some cores, better handling of 32->64 bit compatibility) and MIPS proAptive core beats ARM Cortex A15 on benchmarks.

Статья в MIT Review - по наводке от 1i7

Заработал первый компьютер на карбоновых нанотрубках!


В первом компьютере на карбоновых нанотрубках используется подмножество архитектуры MIPS


Вы в детстве были болельщиком какой-нибудь футбольной команды?

Да. Спартак - Чемпион!
Да. Динамо Киев - Чемпион!
Да. Пояснить в комментариях
Не был
Из-за бугра плюете?

[User Picture]From: maxdz
2013-09-28 12:00 pm (UTC)
Мдя... Похоже, лет через 20-30 C++ умрёт даже в эмбеддед разработке.
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[User Picture]From: panchul
2013-09-28 12:06 pm (UTC)
??? А C++ тут причем?
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[User Picture]From: _iga
2013-09-28 01:01 pm (UTC)
Включая lwl, lwr, swl, swr ? :-)
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[User Picture]From: panchul
2013-09-28 01:04 pm (UTC)
Однозначно нет - по transistor count не выходит :-)
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[User Picture]From: cheeha
2013-09-28 01:09 pm (UTC)
Бедняжка Санта Клара из кремновой станет угольной. :))
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[User Picture]From: panchul
2013-09-28 01:16 pm (UTC)
А когда-то могла стать Германиевой или Арсенид-Галлиевой!
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From: realurix
2013-09-28 02:30 pm (UTC)
Запасов угля там маловато.
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From: realurix
2013-09-28 02:26 pm (UTC)
Не понимаю, чем архитектура 4004 отличается от MIPS. И чем вообще одна архитектура отличается от другой. Это всё какие-то холиварные пляски-войны. Есть машина Тьюринга. И всё. Остальное - от лукавого. Не, ну я конечно понимаю, что кто-то считает, что яйцо нужно разбивать с тупого конца, а кто-то этого не приемлет по жизни и разбивает только с острого. ;-))) Какая разница, если в любом случае яйцо будет разбито.

Edited at 2013-09-28 02:29 pm (UTC)
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[User Picture]From: dom3d
2013-09-28 02:44 pm (UTC)
Юра, а что нам дает первый компьютер на карбоновых нанотрубках?

Ты самое главное не написал. Или это бааальшой секрет.
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[User Picture]From: panchul
2013-09-28 04:24 pm (UTC)
ХЗ. Чего обычно ждут от транзистора на новой основе? Higher density, higher switching rate, lower power.
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[User Picture]From: gineer
2013-10-03 04:05 pm (UTC)
ничего не дает

потому что, до современного количества транзисторов... им еще как до Марса... раком. :))
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[User Picture]From: freedom_of_sea
2013-09-28 04:45 pm (UTC)
как они засунулм нанотрубки в мелкосхему?
пинцетом? Это же технологический тупик!
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[User Picture]From: kelavrik_0
2013-09-28 07:31 pm (UTC)
Интересно, а что-то хорошее из кубитов слепили?
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[User Picture]From: gineer
2013-10-03 04:03 pm (UTC)
вообще-то и то не правда
у 4004 было всетаки уже 2300 транзисторов.
да и производился он массово
так что, ребяты сильно пробуют выдавать желаемое за действительное.
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[User Picture]From: Dmitry Skiba
2013-12-27 07:41 am (UTC)

Сборная Камеруна

Очень нравился Роже Мила. Сильно переживал когда они проиграли Англии
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