[koide]

I guess you mean efficient in that they produce a shorter (or even the shortest) sequence of moves to solve a given scramble. But if it takes 5 minutes of computation to produce the solve, then in practice they are not yet very efficient.

[exitb]

By computation in this case I mean evaluating the state of the cube after a series of moves. It’s extremely difficult for a human, but a computer can simulate millions of moves in a fraction of a second. So realistically, any modern computer can find a low rotation count solution to any scramble almost instantaneously.

[MayeulC]

it depends how much you value a move, vs a computer instruction.

Get a faster computer and a larger cube, the trade-off is likely worth it. A rubik's cube isn't such an intractable problem, I doubt a computer can't solve it faster than a human: in the worst case, they can rely on the same algorithm. Then, they can try to find shortcuts or just shorter paths.

I always thought minimizing the number of moves was the goal, hence "more efficient" made sense to me too.