AMD's range-topping Radeon R9 290X has been (officially) shrouded in mystery since its unveiling last month, but the company is at last revealing full details and releasing the graphics card to stores. As you'd expect given its $549 price, the flagship is a big leap in performance over the $299 R9 280X: it carries 2,816 stream processors, a wider 512-bit memory bus and a larger 4GB of video RAM. The board can muster 5.6TFLOPs of general computing power, AMD says, and is built with 4K graphics in mind. More importantly, it's also delivering a lot of bang for the buck. Early reviews at sites likeAnandTech and Tom's Hardware show the R9 290X outperforming the more expensive GeForce GTX 780; as long as you can tolerate the noisier cooling, it may be a good fit for your gaming PC.