Slashdot Mirror
Magnetic Processors - Computing's New Future?
metalcoat writes "For the first time researchers have created a working prototype of a radical new chip design based on magnetism instead of electrical transistors. As transistor-based microchips hit the limits of Moore's Law, a group of electrical engineers at the University of Notre Dame has fabricated a chip that uses nanoscale magnetic "islands" to juggle the ones and zeroes of binary code.
Wolfgang Perod and his colleagues turned to the process of magnetic patterning (.pdf) to produce a new chip that uses arrays of separate magnetic domains. Each island maintains its own magnetic field. Because the chip has no wires, its device density and processing power may eventually be much higher than transistor-based devices. And it won't be nearly as power-hungry, which will translate to less heat emission and a cooler future for portable hardware like laptops."
"For the first time researchers have created a working prototype of a radical new chip design..."
I thought this had already happened when they moved from straight cut to crinkle cut??
Time is an illusion. Lunchtime doubly so. - Douglas Adams
Will these new processors work when the Earth's magnetic field eventually flip over?
Since magnetic monopoles dont exist, you have to use magnetic dipoles or higher order moments. this translates in to macoscopic structures. It's hard to see how this could beat monopole electrons in size or group velocity. As for power consumption, it's true that magnetism can have low queiscent power consumption because of it's hysterises making it non-volatile. But you pay aprice for this when you have to switch it's state. on the other hand the ideal transistor consumes no power when it is not switching states. If you got rid of the hysteresis in magnetism to make it faster and lower power then it too will become volatile like electronics.
I can see how this could create dense active bulk storage, such as was done long ago with magnetic bubble memory. But I'm skeptical about a pure magnetic logic system beating electronics.
Some drink at the fountain of knowledge. Others just gargle.
"For the first time researchers have created a working prototype of a radical new chip design.."
Hmm. Maybe.
But this seems a lot like bubble memory to me.
And while the wiki entry doesn't mention using this for direct computation, it is indeed possible.
I didn't see anything in the article about the magnets being faster than transistors. Yes, being able to cram more onto a chip will make a faster processor but are the magnetic "islands" faster in and of themselves?
As transistor-based microchips hit the limits of Moore's Law
The submitter speaks of Moore's law as if it were some actual law governing the physics of silicon based integrated circuits. His "law" was nothing more than an observation regarding the time it took the industry to pack more transistors into a given space. It makes no assertions regarding maximum transistor density, heat dissipation, or any of the other physical limitations chip manufacturers keep overcoming.
Dan East
Better known as 318230.
Electicity... magnetism... Bah. Show me a processor working entirely by gravity!
I degaussed the monitor on the cart in the computer room and reset every processor in the compute farm!
The chip industry spends billions in R&D to extend the performance growth of silicon chips. A very large number of engineers know how to design efficient fabs for silicon. Until this technology also attracts a sufficient following of $ and manufacturing experience, I won't count silicon out.
Also, it's not clear that this technology isn't subject to same "limits of Moore's law" (if there is such a thing) as silicon chips. The use of electron-beam lithography would seem to mean that this technology is subject to the some of the same feature-size and practicality limits suffered by silicon chips.
Perhaps this technology will find a place somewhere, it just faces a major uphill battle if it is to supplant silicon.
Two wrongs don't make a right, but three lefts do.
...and next you'll be telling me that tabletop fusion has been discovered, there are parasitic viruses that alter the host's behavior, and that someone invented the plasma drive at NASA. You're ready to swallow all that pseudoscience and yet you all deny me when I try to inform you about the return of the Niburu and Planet X by the great Zecharia Sitchin!!! It's unbelievable just how gullible the Slashdot crowd is and how blind they are to honest truth.
-"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
This supervisor poured much time and effort into his team, investigating various concepts of magnetic computation. Then the integrated circuit came along and turned him into a ruined man.
So have we finally come full-circle now, back to magnetic computation? Call me conservative but I don't think it will fare any better this time around.
True, an ideal CMOS doesn't have any leakage; these days, however, the very small feature sizes translate into more and more leakage, mainly because of the tunneling effect. It's not uncommon for the leakage power to be one fifth of the entire power consumption; unfortunately, with future generations, this will only get worse.
The Raven
Wikipedia entry for Magnetic Bubble memory. I worked on Magnetic Bubble memory at IBM san jose, and the wired article sounds like this is the nano-scale version of this with some big improvements in how they are manipualted. Back then the "bubbles" were a few microns in size. You patterns permaloy onto the surface of a magnetic material. Usually this was a long loop of almost touching chevrons or T-shaped permaloy elements. the bulk materila was polarized one direction (normal to the chip) and inversions in this formed round "bubbles" for reasons simmilar to surface tension these bubbles were stable in one size and liked to stick to the chevron. Under a polarized light microscope you could see the "bubbles" in contrast sticking to the chevrons, giving them their name due to their appearance. one bubble stuck to one chevron. and the presence or absense of a bubble on a chevron was a 1 or 0. in some fancy schema the bubbles could hold internal higher order domain structures to encode more than one bit per bubble but these were never made practical.
A rotating magnetic field transverse to the chip would cause the chevrons to act like little iron bar bagnets pulling the bubble from one side to the other. because the chevron shape is asymetric it acted like a rachet and would only move the bubble unidirectionally. If the field was strong enough the bubble would then "leap" to the next chevron. Under the microscope you saw marching "bits" moving along. so you could move all the bit patterns like a train along the tracks in a bulk matterial with one layer of passive patterning. at one point in the loop track you placed a reader and a writer. this way you had sequential access to any bit and could inject or delete bits in the train.
When the power went off the bubbles stayed put.
It never made it to market (fuji made some) because it's niche was too small. it was slower than ram but faster than a hard drive. it was cheaper than ram but more expensive than a hard drive. At the time it was denser than ram but less dense than a harddrive. Thus it's only use was as a cache between ram and harddrives and in applications where robustness and non-voltility would be valuable like high-radiation sattelites and point of sale terminals. The latter market was eaten by EAROM and then flash memory.
this new material sounds like it uses simmilar concepts but is much smaller and actually performs bubble logic. Not sure about where the clock comes from: perhaps it's still a rotatin mag fiield?
Some drink at the fountain of knowledge. Others just gargle.
I bet one of two things happens. Either someone tries to patent it 5 years after being on the market, and perhaps succeeds since by then patent agents will only have 8 seconds to decide if an idea is patentable, or somebody currently has an obscure patent of a vague rough idea that they never produced that sounds slightly similar to this, which doesn't show up on searches, and they'll keep quiet about it until this thing makes billions and then say "Hey, you owe me money!".
They say that a magnetic insulator would have to be used to shield the chip from external interference.
Magnetic circuits have been studied for at least 80 years. The basic problem is one of size and speed. A dipole magnet (onr with N and S poles) has a certain minimum size, otherwise it depolarizes itself. That sets a minimum size for any magnetic device. Also it's hard to make magnetic amplifiers with more than a small fan-out. It's also really hard to distribute a clock signal-- magnetic pulses fall off at a 1/r^3 rate, and generating a fast magnetic pulse gets blocked by the inductance of the coil.
Now there *are* cigarette-pack to Taj Mahal sized magnetic voltage regulators in use. Your PC power supply may be using one to regulate the 3.3 volt output. But getting them down to IC-size is going to be really hard to impossible.
Magnetic bubbles move. Its principle resembles that of delay line memory used in computers before the invention of core and disk memory: You have huge circulating loops one can access at choosen spots to read a record. (People are working on optical delay line memory to store petabytes and picosecond speeds.)
I interpret this new magnetic technology to be a more compact implementation of programmable logic arrays . PLAs are standard tool in digital circuit design and can theoretically emulate any other digital state machine such as a CPU. Engineers like them because they are like blank circuits you can quickly burn a pattern in them. New high-density PLA chips in the 1980s lead to the rise of the mini-supercomputer industry, with companies like Convex using them. However, general purpose CPUs from Intel and Sun eventually exceeded 1990s PLA speeds and circuit capacities.
I have about 128 bits of it sitting in my closet somewhere. It is not based on a power of two like ram is now, but the length X width of the number of magnets on each side.
A close-up picture of it
It's actually beneficial that a single 'gate' element can perform AND, OR, and INVERT
functions all in one stage. The early TTL won over other logic designs in part because
the basic gate used multiple emitters on the input transistor to get an AND function,
and multiple input transistors to get the OR function. That meant that the delay
and complexity character of AND and OR were the same, and that the complex function
of AND/OR/INVERT was available as a fast multiplexer, with the same characteristics
as a simple NAND. There was a brief attempt to use expandable gates (making
the connection point after the input transistor available on an external pin,
which was NOT TTL-logic-level compatible), but it didn't catch on.
CMOS, on the other hand, had input impedance and delay differences in the AND and
OR and other gates, so the whole 4000 series CMOS logic family only became
trouble-free to use AFTER THEY BUFFERED THE WHOLE FAMILY with an extra inverter
(and consequently extra time delay). Buffered (4000B series) is the common small
scale CMOS you see today, the unbuffered (4000A series) has been sidelined.
From a circuit-design viewpoint, the AND/OR/INVERT is a very good starting element,
for a lot of reasons that only show up when some poor engineer is perspiring over his
timing budget...
To 'shield from magnetic fields' is generally the same thing as 'generate an
opposing magnetic field'; that means the shield materials ARE affected,
and are in fact somewhat magnetized, to create the shielding
effect.
The best shield materials are superconductors (which only exist at low
temperatures). The most common magnetic shield materials are soft
iron alloys (Permalloy and Mu-Metal are brand names). Shielding
from rapidly-changing magnetism is easier, most electrical conductors
will do this (but superconductors do it for constant magnetic fields
as well as changing ones). A weak shielding effect is called diamagnetism,
and is interesting in its own right. Did you know that water is repelled
from a magnetic field? Water is diamagnetic (weakly). Brass is more highly
diamagnetic.