In an interview with PC Games Hardware, AMD's Polaris 10 Senior Product Manager Evan Groenke dispelled rumors about the Polaris 10 GPU having 40 compute units. Groenke confirmed that with its 36 compute units (2304 shaders), the Radeon RX 480 has the full Polaris 10 configuration.
PCGH: Is the P10 a 36-CU-part and no hidden additional CUs?
Evan Groenke: I can absolutely confirm with you right here, that Polaris 10 in its full configuration defined by the silicon is a 36 Compute Unit configuration there's nothing else hidden on that product that end users might be looking forward to unlocking. This is the pinnacle, the latest and greatest of the Polaris 10 product.
This confirms that a possible Radeon RX 490 will not be based on Polaris 10. AMD's naming scheme hints that we may see something like a Radeon RX 485, which would be based on a second-generation Polaris 10, but those desiring more performance from the red team will have to wait until the arrival of the Vega architecture.