bb1=CPUNXT same reference. BB1 is actually the whole cabinet in it's entirety, cpunxt is the generation used, but they are essentially referring to the same platform. There were two iterations of the cpunxt, the one you show on your photo with the green pcb, and a newer version with a blue pcb. The green one had a 700mhz cpu and the blue one had a 650mhz cpu, they switched to the lower speed because it uses less power and generates less heat. I have found the performance to be about the same for both, not really noticeable.