TX-1 CPU - How many cores?

I have seen specs for the TX-1 listing the CPU spec as:

“four Cortex-A57’s”

and also

“four Cortex-A57 CPU cores (max frequency of 1.91GHz) and four Cortex-A53 low-power cores”

I am confused. If the latter is true, is this not a “Octa Core” (as in 8) CPU’s, and of so, what are their speeds.

What the scoop?

Thanks in advance,

Joe

There are 4 main core A57s. There are 4 A53 shadow cores. There is an A9 audio processing core. Only the main cores show up in the operating system listings. The other cores do specialty processing.