The problem is that the "non-optimized" solutions assume that every quibit can talk to every other one. So they are modelling what the quibits should do in a pe

The problem is that the "non-optimized" solutions assume that every quibit can talk to every other one. So they are modelling what the quibits should do in a perfect case and modelling the perfect case is much slower than modelling what we actually have. So the fastest ones are the ones that say, oh, the best answer that the D-Wave is going to give will be X so I don't need to be any more accurate than that. I'll just model the bare minimum necessary to have the same accuracy as the D-wave. Its like lossy compression vs lossless compression. If you are willing to have lossy compression you can do much better and faster. The D-wave is lossy (because it has a "sparse connectivity structure") and thus the other solutions which are also lossy are better comparisons on a speed benchmark.