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A Look at Photonic Clocking
zymano writes "In an article on the Electronic Engineering Times site James Siepmann shares a few thoughts about Photonic Clocking. Siepmann states: 'Copper interconnects are reaching their limit as data-transmission bandwidth and processor speed continue to rise. [..] Photonic clocking not only solves the limitations of electronic clocking, but also reduces jitter, skew, delay, crosstalk and power consumption while maintaining clock signal integrity for longer distances.'" Are Photonic Processors the next logical step, or will the almighty buck shuffle them aside because of cost?
" Are Photonic Processors the next logical step, or will the almighty buck shuffle them aside because of cost?"
You tell us. Ultimately it's your present purchases that will fund it.
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The "are you a script" word for today is rubbers.
If photonic processors go into widespread usage, it will probably be because of the almighty buck and companies deciding that they can make more of it by producing photonic processors.
Profits and competition are the main reason for a lot of the recent advances in processor performance. Look at the processor introductions back when 486 and pentium processors were around and Intel didn't have any credible competition.
"When you sit with a nice girl for two hours, it seems like two minutes. When you sit on a hot stove for two minutes, it
This makes it sound like "the almighty buck" is the bad guy. I think this is one of those times when that's not the case. If fully photonic processors turn out to work best, then that's what we'll see. If they're not, and if the article claim that copper interconnects are reaching their limit is true, then we'll seem some hybrids. Rock on.
This whole article seems like an attempt to pad out a slow news day. Maybe we can turn this article into something useful, or at least more entertaining. We could start a flamewar! Yeah!
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<enganging fake troll mode>It's gotta be Photonic chips all the way man!!! Copper procs, yer all gonna burn in silicon hell!! yeah, burn baby burn! I unleash light-based clocking on all you 1nf1d3l5!!
(etc)
Furry cows moo and decompress.
Assuming that the clock circuity takes up 30% of the chip, wouldn't manufacturing a chip with both photonic and electrical circuitry be more expensive than just manufacturing a purely photonic chip?
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clockless CPU's, which of course--wait for it--don't need a clock. (I realize that other system parts may still need it.) Every once in a while, I hear a tiny thing about clockless chips, but it seems like the Big 2 don't want anything said about them.
Reminder: this comment is on topic.
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Consider the semiconductor. The way we work today is based on binary elemental logic-- on, off, unknown/neutral. Your basic light switch (SPST) is your basic computer, but it can't count too well.
The evolved state of computing uses Boolean logic to mosh states together into integer algebraic, then other kinds of math transformations.
Now, consider what light does, and how it flows. Light (actually this segment of the electromagnetic spectra) has different frequencies, at about the same data rate depending on media. No information there, except frequency differences and blendings of frequencies... lambda moshing.
You can modulate light, like any other electromagnetic phenomena. You can modulate information, therefore, onto light. It's done all the time. By adding information, you can blend things together, then demodulate them to see what happened as the change in information. This modulation mimics how ALUs/accumulators/CPUs work with logic states in some ways, but now we have to multiply the effect to get to significant digits and significant logic handling-- math by light modulation and the devices that can do that. But not densely, so far, in the calculative/logic-state change tracking sense.
What of these devices-- aye, thar's the rub. Is there an advantage to using light to do math? Not yet, really. It doesn't meet the state change efficiency model. One day, it might. Today, we lack the ability to make things dense enough. That's why photonic logic may fall short of expectations.
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It might not be compensation, instead it might be the benefit of the power savings if it's significant enough. If this would double the uptime of a battery powered notebook it might be worth it even if it costs more.
The man who trades freedom for security does not deserve nor will he ever receive either. - Benjamin Franklin
Fiberoptics are superior to purely electrical designs but only after they've overcome the initial investment hurdle for design and implementation.
fast as fast can be. you'll never catch me.
A processor, greatly simplified, is a collection of logic gates. These logic gates, greatly simplified, are nothing more than modulators. In hardware design, the modulation of the electrical signal indicates the result of the logical function of the circuit. Electrical impulses are measured in cycles/second.
:)
Photons can achieve frequencies in vast excess of current processor speeds. The function of a photonic logic gate would be measured by simple amplitude modulation. A photon has a frequency and an amplitude. Using a photon with the energy of a gamma ray would be _FAST_, have negligable heat loss due to the friction which plagues electronic processors, and the amplitude of the photon could be easily modulated by passing through different materials. Different materials of different refractive indeces and transparencies (see fiberoptics) would be the photonic equivalent of electronic resistors and capacitors.
I can only wait for the development of photonic processors.
fast as fast can be. you'll never catch me.
No, really. As soon as it gets anywhere near a point where there's a large-enough market for it, it'll be sold. Witness the present collection of chips - do you *really think that the majority of people using computers need a P4 at >3 GHz? No, they don't. The minute the niche market of gamers (and, yes, it'll be gamers) who can afford it is large enough, it'll hit the market.