A line of video cards made by ATI and the next series after the standard Radeon series. These video cards are typically stronger, faster and have more features such as Eyefinity, ATI Stream, and Avivo HD. However, the latest cards are relatively large and quite expensive. The latest is the HD 5970 which is known as on of the fastest cards to date. The latest series in the Radeon HD line is the 5XXX series which was meant to have Microsoft's DirectX11 integrated and widely available on the market.
Man: "Dude!!! I just got a Radeon HD 5970 for my computer!!! It's gonna pwn some ass!!!"
Friend: "Do you have a full tower case to fit it in?"
Man: "..... @%$#!!!"