8 ms·

A reprieve for Moore’s Law? Work on gallium nitride semiconductors

54 points by bootload 10y ago

petra 10y ago
As far as i can tell this has no relation to moore's law. Moore's law currently suffer mostly due to:limits of manufacturing small things, and mostly because of energy consumption and delay of wires. Without solving those, it would be hard to offer big improvements. And GaN can't solve those afaik.
- jacquesm 10y ago
  For a given size transistor the GaN element will switch considerably faster than the Silicon equivalent. We have an enormous amount of knowledge about the Silicon based process though and it's a bit like trying to come up with a better combustion engine: it may not be the best material to begin with but it will be very hard to catch up with 50 years of materials science and process technology on Silicon. It's a huge head-start, but I'm happy that people are looking at alternatives to Silicon. Bismuth based compounds are interesting as well.
  - petra 10y ago
    Sure it's great that people research things. >> For a given size transistor the GaN element will switch considerably faster than the Silicon equivalent. Most of the delay today is because of wires, not transistors. See figure 1 at http://www.monolithic3d.com/blog/previous/3 http://www.monolithic3d.com/blog/previous/3 .
- marcosdumay 10y ago
  Everything else being equal, faster switching means lower power consumption for CMOS.
akuma73 10y ago
It's not as if Intel and others haven't looked at this and other III-V materials. These GaNs seem to be more suited towards amplifiers and a replacement for the kinds of components that GaAs is currently used - not digital logic. For a look at a potential III-V materials for use in digital logic, have a look at this article. http://www.extremetech.com/gaming/203926-analyst-intel-will-adopt-quantum-wells-iii-v-semiconductors-at-10nm-node http://www.extremetech.com/gaming/203926-analyst-intel-will-... IMHO, Moore's Law will end in about 2019-2020. No exponential can go on forever. This will have huge ramifications for silicon valley. You're already seeing a slow-down. Ever wonder why Intel chips aren't getting all that much faster?
- api 10y ago
  My take on what it will mean: (1) It will now make sense to invest in the development of higher-order compute architectures that take advantage of truly massive parallelism. In the past such efforts (connection machine, etc.) were killed by Moore's Law-- by the time they hit the street CPUs had already gotten so much faster their advantage had disappeared. (2) It will also make sense to prioritize parallelism in software to a much greater degree than it has been historically. (3) "Software Moore's Law" type efforts will get a huge boost. In the past we've almost had an "Eroom's Law" in software: it bloats in proportion to faster chips and more RAM. Expect to see performance in software become a real feature. (I think we're already seeing this.) (4) Slow languages will become considerably less shiny. Fast languages that take good ideas from slower dynamic languages like Rust, Go, Swift, etc. will become much shiner. C/C++ might also see a renaissance in mainstream interest. (This is already happening.) (5) Once fabs all catch up to the state of the art endpoint fab tech for conventional chips, silicon fabrication will become a commodity service subject to commodity market forces. It will get cheap. This will accelerate even more as patents expire (or China ignores them). (6) China (and specifically the Shenzhen ecosystem) has a very good chance of eating semiconductors due to #5. Nobody does manufacturing scale like the Chinese and once they catch up they'll own it unless players like Intel get serious about getting ahead of this. (7) Also due to #5, the price per unit of compute may continue to fall for some time after Moore's Law hits the wall -- and partly because Moore's Law has hit the wall. Something akin to the current top-end Xeon could easily cost under $20 in 10-15 years. Smallish ARM chips could be priced by weight like a building material. (8) As a consequence of #7, we might see what I call "Moore's Mushroom" -- a geometric fall in the price of massively parallel machines (also see #1). If the equivalent of a 48-core Xeon is $20, then a 1200-core monster might cost under $1000. For $10k you'd be able to buy your own equivalent of a decently sized data center. (9) Power efficiency of chips may continue to improve for a while to the extent that this can be pursued without increasing density, and it might make sense to make this a huge priority once density is stable. Power/compute might still have a ways to go. (10) As a consequence of #5, open source core designs will really hit the mainstream. You'll be able to take an open reference chip design and have it fabbed by the lowest bidder. "White label" OSS chips will appear. (11) Finally, also due to #5 ASICs will get cheaper to make. Expect to see more of them, especially since it will now make sense to make an ASIC to speed up an algorithm as you can no longer just wait on Moore's Law to give you that speed for free. You'll see AI ASICs, crypto ASICs, graphics ASICS, data compression ASICs, even language specific 'accelerator' ASICs like JavaScript coprocessors, etc. With OSS core chip designs these could easily get bolted on, leading to weird custom cores like a "JavaScript optimized OpenRISC white label CPU." (12) It might still be possible to push single-threaded performance by improving cooling, e.g. by mainstreaming liquid or active refrigerated cooling. The current overclocking record for cryogenically cooled Xeons is around 6.2ghz. Will we see liquid nitrogen in data centers as a common thing? (13) The PC and mobile device upgrade cycle will slow a lot, which will further kill profits in hardware all the way up the stack. Hardware's about to become a hard business. TL;DR: price/compute and power/compute will continue to improve for a while; semiconductor margins will get squeezed; software efficiency will matter more; ASICs will get more common; open source chips might finally arrive. All of this might actually be good for Silicon Valley, which mostly does software not hardware. Software's about to get even more important.
ridgeguy 10y ago
Another wrinkle in GaN semiconductors is GaN RF power transistors with grown-on diamond heat spreader layers. Increases RF power density by 3x over GaN on SiC. Brief overview here (2014): http://www.edn.com/design/wireless-networking/4435899/History-of-GaN-on-Diamond-Technology http://www.edn.com/design/wireless-networking/4435899/Histor...
nemock 10y ago
Maybe this shouldn't have been called a law. Maybe, "Moore's observation" or "Moore's postulation" would have been more apt.

54 points by bootload 10y ago

petra 10y ago

As far as i can tell this has no relation to moore's law. Moore's law currently suffer mostly due to:limits of manufacturing small things, and mostly because of energy consumption and delay of wires. Without solving those, it would be hard to offer big improvements. And GaN can't solve those afaik.

jacquesm 10y ago
For a given size transistor the GaN element will switch considerably faster than the Silicon equivalent. We have an enormous amount of knowledge about the Silicon based process though and it's a bit like trying to come up with a better combustion engine: it may not be the best material to begin with but it will be very hard to catch up with 50 years of materials science and process technology on Silicon. It's a huge head-start, but I'm happy that people are looking at alternatives to Silicon. Bismuth based compounds are interesting as well.
- petra 10y ago
  Sure it's great that people research things. >> For a given size transistor the GaN element will switch considerably faster than the Silicon equivalent. Most of the delay today is because of wires, not transistors. See figure 1 at http://www.monolithic3d.com/blog/previous/3 http://www.monolithic3d.com/blog/previous/3 .
marcosdumay 10y ago
Everything else being equal, faster switching means lower power consumption for CMOS.

akuma73 10y ago

It's not as if Intel and others haven't looked at this and other III-V materials. These GaNs seem to be more suited towards amplifiers and a replacement for the kinds of components that GaAs is currently used - not digital logic. For a look at a potential III-V materials for use in digital logic, have a look at this article. http://www.extremetech.com/gaming/203926-analyst-intel-will-adopt-quantum-wells-iii-v-semiconductors-at-10nm-node http://www.extremetech.com/gaming/203926-analyst-intel-will-... IMHO, Moore's Law will end in about 2019-2020. No exponential can go on forever. This will have huge ramifications for silicon valley. You're already seeing a slow-down. Ever wonder why Intel chips aren't getting all that much faster?

api 10y ago
My take on what it will mean: (1) It will now make sense to invest in the development of higher-order compute architectures that take advantage of truly massive parallelism. In the past such efforts (connection machine, etc.) were killed by Moore's Law-- by the time they hit the street CPUs had already gotten so much faster their advantage had disappeared. (2) It will also make sense to prioritize parallelism in software to a much greater degree than it has been historically. (3) "Software Moore's Law" type efforts will get a huge boost. In the past we've almost had an "Eroom's Law" in software: it bloats in proportion to faster chips and more RAM. Expect to see performance in software become a real feature. (I think we're already seeing this.) (4) Slow languages will become considerably less shiny. Fast languages that take good ideas from slower dynamic languages like Rust, Go, Swift, etc. will become much shiner. C/C++ might also see a renaissance in mainstream interest. (This is already happening.) (5) Once fabs all catch up to the state of the art endpoint fab tech for conventional chips, silicon fabrication will become a commodity service subject to commodity market forces. It will get cheap. This will accelerate even more as patents expire (or China ignores them). (6) China (and specifically the Shenzhen ecosystem) has a very good chance of eating semiconductors due to #5. Nobody does manufacturing scale like the Chinese and once they catch up they'll own it unless players like Intel get serious about getting ahead of this. (7) Also due to #5, the price per unit of compute may continue to fall for some time after Moore's Law hits the wall -- and partly because Moore's Law has hit the wall. Something akin to the current top-end Xeon could easily cost under $20 in 10-15 years. Smallish ARM chips could be priced by weight like a building material. (8) As a consequence of #7, we might see what I call "Moore's Mushroom" -- a geometric fall in the price of massively parallel machines (also see #1). If the equivalent of a 48-core Xeon is $20, then a 1200-core monster might cost under $1000. For $10k you'd be able to buy your own equivalent of a decently sized data center. (9) Power efficiency of chips may continue to improve for a while to the extent that this can be pursued without increasing density, and it might make sense to make this a huge priority once density is stable. Power/compute might still have a ways to go. (10) As a consequence of #5, open source core designs will really hit the mainstream. You'll be able to take an open reference chip design and have it fabbed by the lowest bidder. "White label" OSS chips will appear. (11) Finally, also due to #5 ASICs will get cheaper to make. Expect to see more of them, especially since it will now make sense to make an ASIC to speed up an algorithm as you can no longer just wait on Moore's Law to give you that speed for free. You'll see AI ASICs, crypto ASICs, graphics ASICS, data compression ASICs, even language specific 'accelerator' ASICs like JavaScript coprocessors, etc. With OSS core chip designs these could easily get bolted on, leading to weird custom cores like a "JavaScript optimized OpenRISC white label CPU." (12) It might still be possible to push single-threaded performance by improving cooling, e.g. by mainstreaming liquid or active refrigerated cooling. The current overclocking record for cryogenically cooled Xeons is around 6.2ghz. Will we see liquid nitrogen in data centers as a common thing? (13) The PC and mobile device upgrade cycle will slow a lot, which will further kill profits in hardware all the way up the stack. Hardware's about to become a hard business. TL;DR: price/compute and power/compute will continue to improve for a while; semiconductor margins will get squeezed; software efficiency will matter more; ASICs will get more common; open source chips might finally arrive. All of this might actually be good for Silicon Valley, which mostly does software not hardware. Software's about to get even more important.

ridgeguy 10y ago

Another wrinkle in GaN semiconductors is GaN RF power transistors with grown-on diamond heat spreader layers. Increases RF power density by 3x over GaN on SiC. Brief overview here (2014): http://www.edn.com/design/wireless-networking/4435899/History-of-GaN-on-Diamond-Technology http://www.edn.com/design/wireless-networking/4435899/Histor...

nemock 10y ago

Maybe this shouldn't have been called a law. Maybe, "Moore's observation" or "Moore's postulation" would have been more apt.