Equation 5 · After Moore: The Adaptive Radiation of Compute
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Measured against that floor, today’s mainstream logic is nowhere close, and the gap is large enough to state with confidence even given the uncertainty in any single measurement. The IRDS’s own 2023 logic-device electrical specifications table projects energy per switching event for a high-density logic cell at roughly 0.86 femtojoules in 2023, declining only to roughly 0.4 femtojoules by its 2037 projection even after the roadmap’s full projected run of gate-all-around and CFET architecture transitions [ 4 ] . A femtojoule is 10^{-15} joules; the Landauer bound at 300 kelvin is roughly 2.910^{-21} joules. Even the roadmap’s best-case 2037 projection is therefore still more than five…
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Measured against that floor, today’s mainstream logic is nowhere close, and the gap is large enough to state with confidence even given the uncertainty in any single measurement. The IRDS’s own 2023 logic-device electrical specifications table projects energy per switching event for a high-density logic cell at roughly 0.86 femtojoules in 2023, declining only to roughly 0.4 femtojoules by its 2037 projection even after the roadmap’s full projected run of gate-all-around and CFET architecture transitions [ 4 ] . A femtojoule is 10^{-15} joules; the Landauer bound at 300 kelvin is roughly 2.910^{-21} joules. Even the roadmap’s best-case 2037 projection is therefore still more than five orders of magnitude — over a hundred thousand times — above the thermodynamic floor, and that gap has narrowed only slowly across the entire history of CMOS scaling, because almost none of that historical energy-per-switch improvement was ever aimed at approaching the Landauer bound specifically; it was a side effect of shrinking capacitance and voltage for other reasons.
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