Power and voltage drop
Each summary describes a real run. Say whether the metric lands over or under the number asked, and the measured value is revealed against it. Keys o and u answer, h shows a hint, and Enter moves on. Guessing gets half right, so the score only means something above that. Progress is stored in this browser.
All 8 summaries in this family, with their numbers
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gcd on Nangate45, 45 nanometre: Is the worst voltage drop over 2 percent of the supply?1.14 percent of the supply, so under
Starving the grid tripled the drop and it is still comfortable, because this design draws milliwatts. Voltage drop follows current, and a small block does not pull enough to trouble even a thin grid. The same change on a design drawing amperes is a different story.
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aes on Nangate45, 45 nanometre: Is the worst voltage drop over 5 percent of the supply?9.9 percent of the supply, so over
Nearly 10 percent is past what most projects allow, and it is the current that does it: a control run of the same design with nothing changed drops 9.28 percent, against 9.9 with restricted routing. Half a watt is a different regime from the milliwatts the small block draws. Voltage drop is analysed per design for exactly this reason: the same grid is generous for one block and inadequate for the next.
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gcd on sky130 high density, 130 nanometre, on a 1.8 volt supply: Does this version draw more than 7.9 milliwatts, three times the Nangate45 figure?9.38 milliwatts, so over
9.38 milliwatts, three and a half times as much, despite running at a third of the frequency. The supply ratio alone squares to 2.7, and the larger transistors and longer wires carry more capacitance. This is the whole argument for moving to a smaller node, in one number.
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gcd on Nangate45, 45 nanometre: Did chasing the unreachable target more than double the power?5.6 milliwatts, so over
5.60 milliwatts against 2.62, for a design that still failed timing. Upsizing raises capacitance, repair buffers add more, and the clock they all hang off runs faster. Pushing a block past what it can do costs area and power together, and buys nothing.
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gcd on Nangate45, 45 nanometre: Did spreading the design out raise the power by more than a quarter?9.5 percent, so under
2.87 milliwatts against 2.62, under ten percent, from 69 percent more wire. Most of the power here is the cells and the clock rather than the interconnect, so lengthening the wires moves the total far less than it moves the delay. The cost of a loose floorplan is timing first, power second.
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ibex on Nangate45, 45 nanometre: Does this core draw more than 100 milliwatts?31 milliwatts, so under
31 milliwatts against 472, a factor of fifteen, for a similar amount of silicon. Most of that is the clock: aes runs 2.7 times faster, and its pipeline toggles far more of itself each cycle. Power is a statement about activity and frequency, not about size, which is why a power figure without its operating point means nothing.
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gcd on ASAP7, 7 nanometre, on a 0.77 volt supply: Does it draw more than 2 milliwatts here?1.45 milliwatts, so under
1.45 milliwatts, the lowest of the three, while running at three gigahertz. Lower supply, smaller transistors, and shorter wires all cut switching power faster than the frequency raises it. Leakage is the part that does not improve, which is why modern nodes fight it with threshold choice and power gating.
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jpeg on Nangate45, 45 nanometre: Is the worst voltage drop over 5 percent of the supply?6.9 percent of the supply, so over
6.9 percent on the default grid, past what most projects allow. Density and current work together here: the same grid that is generous for a milliwatt block cannot feed a packed half-watt one. This is why the power plan is a design decision rather than a platform setting.