Is it a waste to set innodb_buffer_pool_instances greater than the # of CPUs?

I set the innodb_buffer_pool_size to 20GB on a server with 12 CPU cores. My full database is 11gb, however most of it is archived tables that are almost never used. The total queried data is around 3 gb, and the frequently queried data is ~1.25 gb.

What should I set the innodb_buffer_pool_instances to?

1. innodb_buffer_pool_size / total queried data = 6 pool instances


2. innodb_buffer_pool_size / frequently queried data = 16 pool instances

Normally I'd pick option #2, but logically it seems number of buffer pools that can be used at any one time is no more than the total number of CPU cores.

Is it a waste to set innodb_buffer_pool_instances to more than the # of CPU cores?