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DARPA Looks Beyond Moore's Law
ddtstudio writes "DARPA (the folks who brought you the Internet) is, according to eWeek, looking more than ten years down the road when, they say, chip makers are going to have to have totally new chip fabrication technologies. Quantum gates? Indium Phosphide? Let's keep in mind that Moore's Law was more an observation than a predictive law of nature, despite how people treat it that way."
I"m pretty excited about the new man-made diamonds that are supposed to be able to keep moore's law going for decades when they come out. Wired had an article recently and a post here on /. too
An educated observation, which is why it basically works.
Please note that the observation was well enough educated that it includes the fact that its validity will be limited in time frame and that before it becomes completely obsolete the multiplying factor will change, as it already has a couple of times.
In order to understand Moore's Law one must read his entire essay, not just have some vague idea of one portion of it.
Just as being able to quote "E=mc^2" in no way implies you have the slightest understanding of the Special Theory of Relativity.
KFG
Moore's law is already ending. Intel's Prescott (i.e. Pentium 5) CPU dissipates 103 watts. That's beyond anything you can put in a laptop, and it's arguably beyond anything that should be in a workstation-class PC. But it also may not be that we're hitting CPU speed limits, just that we're hitting the limits of type types of processors that are being designed. Much of the reason the PowerPC line runs cooler than the x86 is because the instruction set and architecture are much cleaner. There's no dealing with calls to unaligned subroutines, no translation of CISC instructions to a series of RISC micro-ops, and so on. But there are the same fundamental issues: massive amounts of complexity dealing with out of order execution, register renaming, cache management, branch prediction, managing in-order writebacks of results, etc.
Historically, designing CPUs for higher-level purposes, other than simply designing them to execute traditional assembly language, has been deemed a failure. This is because generic hardware advanced so quickly that the custom processors were outdated as soon as they were finished. Witness Wirth's Lilith, which was soon outperformed by an off-the-shelf 32-bit CPU from National Semiconductor (remember them?). The Lisp machine is a higher profile example.
But now things are not so clear. Ericsson designed a processor to run their Erlang concurrent-functional programming language, a language they use to develop high-end, high-availability applications. The FPGA prototype was outperforming the highly-optimized emulator that had been using up to that point by a factor of 30. This was with the FPGA at a clock speed of ~20MHz, and the emulator running on an UltraSPARC at ~500MHz. And remember, this was with an FPGA prototype, one that didn't even include branch prediction. Power dissipation was on the order of a watt or two.
Quite likely, we're going to start seeing more of this approach. Figure out what it is that you actually want to *do*, then design for that. Don't design for an overly general case. For example, 90% of desktop CPU use could get by without floating point math, especially if there were some key fixed point instructions in the integer unit. But every Pentium 4 and Athlon not only includes 80-bit floating point units, but massive FP vector processing units as well. (Not to mention outmoded MMX instructions that are almost completely ignored.)
They made an announcement about it less than a year ago. They don't say if they'll be doing anything special about heat problems, though.
Thank Goodness someone has finally said something about it, even if it was just in passing. The bonus is that it is on the front page of Slashdot.
t m
"Moore's Law" is no more a "law" in the sense of physics (or anything else for that matter), than any other basic observation made by a scientist or physicist.
Oddly, you'd have a hard time believing it wasn't a Law of Nature by the apocalyptic cries from the technology industry when "Moore's Law" falls behind - spouting that something *has* to be done immediately for Moore's Law to continue, lest the nuclear reaction in the Sun cease. Or something.
At the time it was coined by the *press* in 1965, only a small fraction of what we now know was known about the physics of integrated circuits and semiconductors at the time. So, looking back it's easy to see that the exponential trend in density would continue as long as the knowledge and abilility to manipluate materials increased exponentially.
Yes, it is rather surprising that Moore's observation has held true as long as it has. And this isn't to say that the growth trend won't continue, but it will certainly level off for periods while materials or manufacturing research comes up with some new knowledge to advance the industry.
As the article indicates, things are likely headed for a plateau, possibly toward the end of this decade or start of the next. And at that point, Moore's observation will simply no longer be true or appropriate.
Let the cries of armageddon begin as "Moore's Law" is finally recognized as an observation that will eventually be outlived.
For a little "Moore" background, see http://www.intel.com/research/silicon/mooreslaw.h