Quantum technology is maturing to the point where quantum devices,
such as quantum communication systems, quantum random number 
generators and quantum simulators, may be built with powers 
exceeding the performance of classical computers. A quantum 
annealer, in particular, finds solutions to hard optimization 
problems by evolving a known initial configuration towards the 
ground state of a Hamiltonian that encodes an optimisation 
problem. In this talk I will present results from experiments 
on a 108 qubit D-Wave One device based on superconducting flux 
qubits and will provide evidence that the device indeed performs 
quantum anealing. To assess the computational power of the 
quantum annealer I compare it to optimised classical algorithms 
and will present first preliminary results for a D-Wave Two 
system with more than five hundred qubits.