The D-Wave Two, 2X, and 2000Q all used the Chimera architecture, which had unit cells of K4,4 graphs. D-Wave machines added more qubits but the cells and architecture were mostly the same.

The Pegasus graph allows each qubit to couple to 15 other qubits instead of 6 qubits.

In mid-2018, D-Wave revealed that they had built 680 Pegasus qubit chip. The D-Wave 2000Q has 2048 Chimera qubits.

Where was D-Wave in 2018?
* annealing options
* reverse annealing
* quantum materials simulation