The Radeon RX 550 normaly has 8 CU, 512 shader and the Polaris 12 gpu.

I saw a RX 550 with 10 CU and 640 shader, and I thought it´s the unlocked version from the Polaris 12 gpu.
But it´s only a renamed Polaris 11/21 gpu with 6 locked cu´s and 1500MHz memory (called Baffin LE).
Another version of the RX560D, only with 10 CU.

I think this card is not good for mining, because the memory is to slow.