Multi-threaded architecture: Solving SHA256 , Scrypt and X11 algorithms ( do we have gpus specializing in each - any links would be useful)
No one's mining SHA256, Scrypt and X11 algorithms with their GPUs, they've been mined with ASICS for a very long time.
Are Radeons (for eg Rx Vega 56) from XFX ATI MSI ASUS or any other company perform same way?
At the moment all RX Vega cards are reference designs, so they're all identical and there's no difference between any of the brands. But it's supposed to change soon, some brands already presented their non-reference cards and we're all waiting for them to hit the stores.