With AMD's Radeon HD 6990's arrival this week, the ball is in Nvidia's court to deliver a competitive alternative. The GeForce GTX 590 was expected to appear sometime last month but obviously that didn't happen. We haven't seen any release dates from Nvidia yet, but at PAX East 2011. The event kicks off on March 11 at Exhibit Hall A, Booth #524 and will let attendees experience today's "hottest" games (including some unreleased titles) in 3D and Nvidia 3D Vision Surround. Nvidia also plans to give away $20,000 worth of prizes along with showcasing various gaming PCs and upcoming Tegra handsets and tablets.