Streams testing and AWR report

I'm trying to get an idea of what hardware will be sufficient to support streaming an application from our production database. In this effort, I searched Google and found:
http://www.dba-oracle.com/t_streams_benchmarking_testing.htm

While I understand the findings, I don't understand the report. Specifically, why is the Elapsed at 2.62 minutes and DB Time at 74.32 minutes. I would have thought this due to the number of CPUs on the system, but looking further down under "Operating System Statistics" at the statistic "NUM_CPUS" it is 2. Am I missing something?

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