Even if it's fake, the very quick Super Pi time brought up a discussion at OCF:

Since each module has shared components, and the hardware does the splitting of resources, even if Super Pi is a single-threaded program, it will be split up between the two "cores" in the single module because the resource allocating is done via on-chip hardware, and not the software. Which is like getting two cores to computer Super Pi, but it's still single-threaded.