3 ms·

How does binning work when your chip is the entire wafer?

• shrubble 2y ago
  They expect that some of the cores on the wafer will fail, so they have redundant links all throughout the chip, so they can seal off/turn off any cores that fail and still have enough cores to do useful work.
  • why_only_15 2y ago
    My understanding is that they mask off or otherwise disable a whole row+column of cores when one dies
    • wtallis 2y ago
      That's way too wasteful. Take a look at https://fuse.wikichip.org/news/3010/a-look-at-cerebras-wafer-scale-engine-half-square-foot-silicon-chip/2/ https://fuse.wikichip.org/news/3010/a-look-at-cerebras-wafer... and specifically the diagram https://fuse.wikichip.org/wp-content/uploads/2019/11/hc31-cerebras-mem-yield.png https://fuse.wikichip.org/wp-content/uploads/2019/11/hc31-ce... The fabric can effectively route signals diagonally to work around an individual defective core, with a displacement of one position for cores in the same row from that defect over to the nearest spare core. That's how they get away with a claimed "1–1.5%" of spare cores.