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Paint-on Laser Brings Optical Computing Closer
holy_calamity writes "New Scientist has a story about a laser made by painting a solution of semiconductor crystals onto glass. It could be used to break the interconnect barrier by having optical interconnects, the interconnect barrier threatens Moore's law unless a faster way of connecting chips is found."
Is there any chance this paint is waterproof.
Sincerely,
Dr Evil.
liqbase
Optical interconnects could make for far more reliable connections between system components. Ribbon cables etc break easily, and are a real nightmare for assembly. OTOH, a few specks of dust in an optical connection could cause a lot of grief (reflection etc) making one wonder what the longterm prospects of shipping optically connected products are.
Engineering is the art of compromise.
But, will we have 5 megawatts by mid-May?
Also, electricity suffers resistance when it travels through metal, creating HEAT and LOTS of it (I've heard its not uncommon for the latest P4's to operate around 70dec C under full load with stock cooler). Light on the other hand, travelling through optical cable or through air or vacuum, is offered no resistance (or so little that it barely generates any appreciable heat).
Room temperature processors anyone? This would be great for eliminating the wear and tear and thermal breakdown caused by heating/cooling when turning your comp on and off. I believe the speed difference between electricity and light (while it may be significant through specific mediums) would be negligible? We're talking distances of micrometers, and 2 or 3 cm at worst (think of the size of a processor die).
Chums up, let's do this!
Well, I don't have any direct sources, but: The interconnect barrier means that while chip size keeps decreasing, the interconnects between sections of chips, and even between individual chips themselves aren't able to be made much smaller, so things like resistance, capacitance, and inductance get in the way with the bigger interconnects. Basically, the interconnects can't keep up with the growth of the chips themselves.
Nothing says "unprofessional job" like wrinkles in your duct tape.
It is not the travelling of electrons that gets the electric signal propagating.
.25 and .75c
(IIRC, hams use a factor of around .7c for the speed in a whip
antenna, while tiny ethernet strands only give around .33c).
The travel itself, no. The wavefront of "pressure" moving along the path of the electrons, yes. The electrons themselves move at only (depending heavily on current and wire diameter) around 1-10cm per hour.
But the wave still only travels somewhere between
Does the difference there really matter all that much? For long-distance communication, sure. But for chip interconnects? Doubtful.
yep it's simple really.
take your standard Network. Incoming ISP network, Local Router, cables, computers.
Now take a Fiber optic version of that. Fiber from ISP, to Interconnect, to router, cables and computers. Sometimes they can even make the lines to the machines fiber as well but not always.
Basically in order to have fiber optics everytime you hit a junction you have to convert the signal to electrical, sort it, and then convert it back to light. That process slows down the overall data transfer rate considerably.
What they are trying to do is make it so that you can plug the fiber right into your computer and have the signal remain as light the entire distance it travels. This will increase bandwidth and speed of the networks signifcantly just be replacing routers.
i thought once I was found, but it was only a dream.
"The observation made in 1965 by Gordon Moore, co-founder of Intel, that the number of transistors per square inch on integrated circuits had doubled every year since the integrated circuit was invented. Moore predicted that this trend would continue for the foreseeable future. In subsequent years, the pace slowed down a bit, but data density has doubled approximately every 18 months, and this is the current definition of Moore's Law, which Moore himself has blessed. Most experts, including Moore himself, expect Moore's Law to hold for at least another two decades."
It has to do with transistors.. not the speed of processors.
yes. inductance slows electrons down and electrical traces can't touch each other so they have to be drawn around each other - laser light beans can pass through one another with no interference. So the traces can be more direct and hence faster. Finally, the scale of components in a processor has gotten small enough that individual traces are interfering with one another inductively and on a quantum level - these don't happen with light.
You are checking your backups, aren't you?
The intention of quantum computing is not to replace, but rather to complement classical (i.e. digital) computing. Quantum computing can dramatically speed up certain tasks, such as cryptography and searching. Even though they cannot yet be implemented, a number of important quantum algorithms have already been discovered. Most - but not all - quantum algorithms return probabilistic answers, rather than clear-cut answers as most classical algorithms do.
Shor's algorithm for factoring numbers could be used to rapidly crack RSA encryption. http://en.wikipedia.org/wiki/Shor's_algorithm
Grover's algorithm can be used to search an unsorted database in O(n?2) time. http://en.wikipedia.org/wiki/Grover's_algorithm
this is what you get for NRFA
Well in this case they have developed a way to create an infrared laser small enough to go inside a CPU.
Optical computers Here we come. BSOD's will really turn your computer Blue.
i thought once I was found, but it was only a dream.
Mom?
The article and summary seem to be a bit misleading and vauge about how the speed increase arrises. The great benefit of optical computing is that it allows the signals to get much much closer together than electronic circuits, and as such allow more compact circuits, which as we know generally means faster. Interestingly, electronic signals in wires and optical signals in fibers have roughly identical upper speed limits (light in free-space optical computers is faster, but also almost impossible to do anything useful with), so its the density which is the major factor.
Electrons are charged, so as you squeeze transistors closer together, the wires get thinner and closer together, and you get cross-talk and interference between them. Photons however hardly interact at all, so you can have many beams in the same space, and theres very little heat to be dissipated. Multiplw frequencies can also be used, resulting in massivly parallel computing (another GoodThing).
There are downsides with optical computing still, photons cannot be stopped and stored (easily), meaning any kind of useful computer in the near term is likely to be some sort of electro-optical hybrid, with photons carrying signals and electrons storing them
it wouldn't be that hard to change it from binary (light on/light off) to amounts of light (of course the same thing could be done with electric interconnects but by voltage--just not as consistently)
Didn't the Russians try this at one point? If I remember right, they had trouble distinguishing between the on state, and the not on/not off state, and wound up abandoning the idea because it was too unreliable.
Yes and no. It depends on what the electricity is traveling through (freespace? wire?). Electricty generates heat and noise. Now assuming it takes less electricity to power the lasers then it will generate less heat. I think noise is the main reason. Two wires (general term, wires...traces..) with current flowing through them will affect each other, hence putting noise on each others line. This is ok at low frequencies (slow speeds), but at higher frequencies it distorts the signal up to a point of unusability. So if you replace your wires with light you dont have this problem because two light pipes next to each other will not affect each other. There is a reason why they use optical switching for the internet backbone, its fast (not just because the end product has to be light going through fiber optic cables). The problem these switches right now have to be maid out of exotic materials and cannot be integrated on a chip. Using optical switches inside of a chip is the holy grail. Don't underestimate the importance on advancing optics. If you want computers to keep getting faster we will have to go to optical pretty soon . Within the next 10 years we are expected to hit a barrier with current technology. You watch. Optical will be beating at your door before you know it.
The bottleneck in computing isn't Moore's Law of transistor density. It's programming paradigms. We're wasting the vast majority of processing/memory/transmission capacity with linear programming, rather than parallel programs. Procedural programs are based entirely on the bottleneck paradigm, with the entire system reduced to a single boolean operation at any given time. Any parallelism is exceptional, and difficult to express in the symbols humans send to computers.
Parallel dataflow and distributed control are long overdue to the mainstream. Compilable UML is a slow, crude path to it. When I can draw a flowchart of primitive objects, any of which are packaged procedures or other flowed objects, and watch it run, I'll have a much better shot at exploiting all the compute/storage/transmit capacity available at that time. When "compilers" can distribute my data among the resources according to topology and analytical prediction, I'll finally get full use of the machines I'm using. Until then, I'm doubling my HW capacity every year or two so it can use half the efficiency gain running inefficient software.
--
make install -not war
What the hell do imperfections have to do with it? Nothing with mass can move at the speed of light. You seem to be suggesting that if the conductor was perfect, the electrons could move at the speed of light. What sort of crazy talk is that?
Anyway, the electrons have a net speed on the order of just millimeters per second. However, changes in the electric field caused by the motion of the electrons can propagate through the conductor much, much faster.
For example, suppose you wanted something to operate at 10GHz. Now suppose that the medium you use is such that the wave moves at .5c. That gives you a wavelength of just 1.5cm. That means on larger dies, you can start having signal propagation problems, in that you won't get a wave all the way across the chip before the next ones starts. Plays hell on synchronized processor designs like we use today.
It's not a problem yet, that I know of, but something that we have to think about in the future.
Whoa, your modders are on crack. Your answer is totally offtopic.
Electrons are practically bystanders in the propagation of a signal down a transmission line. The signal itself is an electromagnetic wave different only in wavelength and frequency from any other electromagnetic wave, including light. They play a crucial role at the ends, but in the middle they just slow things down.
You already did, look in the drawer.
The Kruger Dunning explains most post on
[i]the interconnect barrier threatens Moore's law[/i]
Terribly sorry to rain on your parade, but the fact that we live in a 3D world with a speedlimit limits computing speed eventually.
Electrical signals in wires travel (according to rough measurements I did about two decades ago) at about 0.3c (a third of the lightspeed). Light travels at 0.6c (in glass).
So you win about a factor of two by moving to light, provided you use fibreglass to channel the communications to the right place.
If you Aim lasers through normal air, you can win a factor of three. Wow. That might extend Moore another 2 years, but it does not solve the fact that physics limits Moore eventually.
In theory, "computing nodes" can be connected using for example hypercubes. 4 nodes form a square with max communications distance of 2, 8 nodes form a cube, with max distance of 3. And so on.
Wether these "computing nodes" are complete computers, elements of a parallel system, or just elements of a CPU, doesn't matter.
As the dimension of the hypercube increases, the physical placement of the nodes in 3D-space means that the communications links between the nodes starts to increase. The Lightspeed limits theoretical computation speed to what you might expect of a 3D structure.
Off topic, but had to be asked.
You know, your post was good until you ruined it at the end. I have always wondered, but never bothered to ask until now (irritation level reached its limit?)... What the HELL is the obsession with "first post"? Does it make your dick grow longer if you get it or something? A real, tangible benefit?