The animation in the article shows GPT-5.6 Sol Ultrafast solving a question at 3 secs vs Fable's 27 secs. The "11 hour vs 78 hours" animation implied that they were solved in sequence and not in parallel

>Answering 2,500 independent questions is an embarrassingly parallel workload

So is calculating the total time required to answer all of the questions.

i assume they meant serially....

Amadahl’s law dictates it’s approximately always better (as in, more efficient computationally) to have one super fast thing than many slower things doing the same job in parallel.