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Limits to Moore's Law Launch New Computing Quests
tringtring alerts us to news that the National Science Foundation has requested $20 million in funding to work on "Science and Engineering Beyond Moore's Law." The PC World article goes on to say that the effort "would fund academic research on technologies, including carbon nanotubes, quantum computing and massively multicore computers, that could improve and replace current transistor technology." tringtring notes that quantum computing has received funding on its own lately, and work on multicore chips has intensified the hunt for parallel programming. Also, improvements are still being made to current transistor mechanics.
...is a mentality that probably won't work here.
Intel sunk billions into the development of Itanium on the premise that if they make a VLIW architecture, compiler developers will find a way to automatically extract the parallelism necessary to make good use of it. A company with the size, resources, and engineering knowledge of Intel made the mistake of assuming that a fundamental shift in thinking could be driven by money and sheer desire, but it turns out that the problem is not just hard - that would make it solvable given sufficient effort and money - it's actually impossible. Those compiler advances never materialized; you can't draw blood from a stone.
The quest for parallelism in ordinary software might just be similar. Developing tools to make this automated and easy with low overhead is akin to putting a dozen smart people in a room and saying "think up the next big idea that will make me millions." Innovation doesn't work that way; it can't be forced... and money isn't going to make the impossible into the possible.
I think we'll see a move to eight and then maybe even sixteen cores on a consumer-level chip before we see things start going back in the other direction. This will necessary mean a slowdown in the development of processors as CPU manufacturers go back to wringing every last bit of single-threaded performance out of their designs.
Thoughts?
Moore's law is an observation about the cost per transistor in a circuit. Making faster computation is all about transistor density and the distance signals must travel. Even after the 2-D transistor density levels off, the race will be on to make cheaper 3-D chips using wafer-bonding methods, giving us a new dimension to increase density and thus speed up computation:
http://mtlweb.mit.edu/researchgroups/icsystems/3dcsg/
And we'll still see the same exponential benefits to GOPs/$ for a long time after 3-D transistor density maxes out. The economics that drive the exponential cost-per-computation trend are more related to volume of demand which offsets high fixed production costs and less related to our ability to actually cram more transistors on a chip.