EDIT: After typing this up I realized big.LITTLE was mentioned and the article and it what OP was referring to but people may find the explanation useful so I'm

EDIT: After typing this up I realized big.LITTLE was mentioned and the article and it what OP was referring to but people may find the explanation useful so I'm posting it anyways I'm a little surprised no one else has mentioned this yet, but this is exactly what most modern cellphones do, the architecture is known as big.LITTLE [0]. There's basically three ways you can use the extra set of cores: 1. Either all high performance cores are used or all low performance cores are used, but never both. 2. The cores are paired up in twos, where only one member of each pair is active at a time. This is very similar conceptually to the way frequency scaling works in a desktop or laptop chip. 3. All cores are always available for use and processes are scheduled to either a high performance or low performance core as needed. Cores without any scheduled processes can be powered off or put in a low power state