PCMOS Microchip Puts Errors To Good Use
Didn't you hate when your college calculus processor insisted that an
answer had to be "exact," and that "close enough" just wouldn't cut it?
Clearly, you should have attended Rice University or Nanyang
Technological University in Singapore. A team of researchers from both
institutions have come together in order to create a revolutionary type
of computing that thrives on random errors. You read correctly: this
stuff actually benefits from impreciseness.
Dubbed PCMOS (for
probabilistic CMOS), this technology has been used in a microchip that
requires 30 times less electricity while running seven times faster
than today's best technology. The crew unveiled their findings at the
International Solid-State Circuits Conference in San Francisco, and
while it may be tough to fathom, it's the "probabilistic logic" that
enables it to operate with drastically less power. Better still,
PCMOS piggybacks on the "complementary metal-oxide semiconductor"
technology, or CMOS, that chipmakers already use, which means that said
chipmakers won't have to buy new equipment to support PCMOS. As you can
imagine, that's about where the similarities end, as PCMOS ditches the
traditional usage of Boolean logic and replaces it with a radical
probabilistic approach that was conceived by Rice University Professor
Krishna Palem (pictured) and his doctoral student, Lakshmi Chakrapani.
According to Shekhar Borkar, an Intel Fellow and director of Intel's Microprocessor Technology Lab: "A significant achievement here is the validation of Rice's probabilistic analogue to Boolean logic using PCMOS. Coupled with the significant energy and speed advantages that PCMOS offers, this logic will prove extremely important because basic physics dictates that future transistor-based logic will need probabilistic methods."
You see, existing silicon transistors become increasingly noisy as they decrease in size, forcing engineers to deal by
boosting the operating voltage to overpower the noise and
ensure accurate calculations. Clearly, the more the voltage is boosted,
the more power will be wasted in operation. Palem has stated that
"PCMOS is fundamentally different," in that it "lowers the voltage
dramatically and deals with the resulting computational errors by
embracing the errors and uncertainties through probabilistic logic."
As for the future? The Rice-NTU team is hoping to follow-up its proof-of-concept work on encryption with proof-of-concept tests on microchips for cell phones, graphics cards and medical implants. For example, in a streaming video application on a mobile phone, the small display -- combined with the human brain's ability to process less-than-perfect pictures -- "results in a case where the picture looks just as good with a calculation that's only approximately correct."
Palem, who directs Rice's Value of Information-based
Sustainable Embedded Nanocomputing Center, sums up the purpose nicely
with this: "Our goal is green computing. We're looking for applications
where PCMOS can deliver as well as or better than existing technology
but with a fraction of the energy." So, who said imperfections weren't
beneficial in computing?
Dubbed PCMOS (for
probabilistic CMOS), this technology has been used in a microchip that
requires 30 times less electricity while running seven times faster
than today's best technology. The crew unveiled their findings at the
International Solid-State Circuits Conference in San Francisco, and
while it may be tough to fathom, it's the "probabilistic logic" that
enables it to operate with drastically less power. Better still,
PCMOS piggybacks on the "complementary metal-oxide semiconductor"
technology, or CMOS, that chipmakers already use, which means that said
chipmakers won't have to buy new equipment to support PCMOS. As you can
imagine, that's about where the similarities end, as PCMOS ditches the
traditional usage of Boolean logic and replaces it with a radical
probabilistic approach that was conceived by Rice University Professor
Krishna Palem (pictured) and his doctoral student, Lakshmi Chakrapani.According to Shekhar Borkar, an Intel Fellow and director of Intel's Microprocessor Technology Lab: "A significant achievement here is the validation of Rice's probabilistic analogue to Boolean logic using PCMOS. Coupled with the significant energy and speed advantages that PCMOS offers, this logic will prove extremely important because basic physics dictates that future transistor-based logic will need probabilistic methods."
You see, existing silicon transistors become increasingly noisy as they decrease in size, forcing engineers to deal by
boosting the operating voltage to overpower the noise and
ensure accurate calculations. Clearly, the more the voltage is boosted,
the more power will be wasted in operation. Palem has stated that
"PCMOS is fundamentally different," in that it "lowers the voltage
dramatically and deals with the resulting computational errors by
embracing the errors and uncertainties through probabilistic logic."As for the future? The Rice-NTU team is hoping to follow-up its proof-of-concept work on encryption with proof-of-concept tests on microchips for cell phones, graphics cards and medical implants. For example, in a streaming video application on a mobile phone, the small display -- combined with the human brain's ability to process less-than-perfect pictures -- "results in a case where the picture looks just as good with a calculation that's only approximately correct."
Palem, who directs Rice's Value of Information-based
Sustainable Embedded Nanocomputing Center, sums up the purpose nicely
with this: "Our goal is green computing. We're looking for applications
where PCMOS can deliver as well as or better than existing technology
but with a fraction of the energy." So, who said imperfections weren't
beneficial in computing?
