Ubisoft performed several upgrades to the Anvil game engine, resulting in the AnvilNext engine. Assassin's Creed 3 will be the first game in the series to support DX11. Assassin's Creed 3 also supports NVIDIA's new TXAA technology, but will that be enough to make up for a lack of DX11 features like tessellation and ambient occlusion?
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips