Several AMD RX 480 GPUs have been successfully flashed with RX 580 BIOS files, effectively allowing updated RX 480 GPUs to run with the enhanced clock speeds of the RX 580.
This was first done by a user of the Techpowerup Forums called TonybonJoby, who used a Sapphite RX 580 BIOS to “upgrade” his XFX RX 480, allowing his GPU to achieve the same clock speeds as the Sapphire model (1411MHz). Right now the GPU is reportedly stable, though at this time it is unknown if this GPU’s lifespan will be negatively impacted by the upgrade.
BIOS upgrades like this are unsurprising, as AMD themselves have admitted that the RX 580 is powered by the same GPU as the RX 480, with the only change being increased clock speeds thanks to improved manufacturing techniques. There is no guarantee that an RX 480 will BIOS flash to an RX 580, making this performance-boosting BIOS update a risky process.