It seems that the D-Wave Computer does work, and the theory is that the hardware is 3,600 times faster than other supercomputers. It is the nearest we have to quantum computing, and there have been two tests leading to the announcement that it was far more quickly than simulated annealing which is a copy of quantum computation carried out on a standard computer chip.
The results were commented on by Hartmut Neven the Google Director of Engineering. He explained that it was 108 times faster than simulated annealing run on a single core and comparisons had been carried out against Quantum Monte Carlo. Despite running on conventional processors, it copies the quantum system, and there is little to choose when it comes to scaling.
The extra speed can be attributed to a quantum mechanical quirk. Qubits are used, and this means that solutions can be considered more quickly. There is, however, controversy, but Google seems to have demonstrated that quantum effects are solving problems quickly. The D-Wave quantum computer can finish a task 100 million times faster than a standard computer. A peer review still needs to take place, and it can still be shown the average computer was not using the best algorithm available.
Google is still working with NASA and also has its own hardware laboratory. Size and cost are not an issue at present as the main aim is to ensure the computer works. This is the view of John Martinis, who is leading the program at the University of California.