## The decoding backlog problem for the surface code

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I’m looking at slide 11 of https://github.com/bcriger/slide_decks/blob/master/Surface_Code_And_Decoding.pdf :

I do not understand the last line. Why do all the other logical qubits need to be measured during this time? I understand that for $$S_L$$ we need a magic state and we need to feed a measurement eigenvalue forward. I do not understand where $$O(d^6)$$ comes from.