AMD’s new Radeon RX 480 is offered in two flavors, one with 4GB of memory and the other with 8GB. Assuming you could find either card in stock, you’d pay on average around $40 more for the premium model. If you’re one of the lucky ones that got ahold of an early production 4GB model, however, you may be able to double your usable memory by simply flashing the card.
As the story goes, AMD sent out 8GB review samples. To simulate reviews of a 4GB card, they also sent over a special BIOS that converts the 8GB card to 4GB by reducing its address-space and memory clocks. This was supposedly only for review cards but that hasn’t panned out.
According to TechPowerUp, some people that purchased retail 4GB cards discovered they arrived with 8GB of memory physically installed on the PCB. The site’s own 4GB card it purchased was of this variety and after flashing it to the 8GB card’s BIOS, it was recognized and worked as advertised.
They did this by extracting the BIOS of the 8GB card using ATIFlash 2.74 and then transplanting it to the 4GB card. They used the BIOS image found here although as always, note that you’re taking a risk and you’re the only one that will be responsible should things go south.
In testing, the site found that the true 8GB card and modified 4GB card performed on par with each other.
Apparently the only way to determine if your card physically has 8GB of memory is to remove the factory cooler which will likely void your warranty. Whether or not the risk is worth $40 will be for you to decide.