Autodesk AutoCAD 2011 (Version 18.1) was released on March 25, 2010, as a major update focused on enhancing both 2D and 3D design workflows
To run the 64-bit version effectively, your hardware must meet these official specifications Operating System Autodesk AutoCAD 2011 -64-bit-
AutoCAD 2011 64-bit introduces several new features, including: Autodesk AutoCAD 2011 (Version 18
32-bit systems could only address about 3.5GB of RAM. Autodesk AutoCAD 2011 -64-bit-
Keywords integrated: Autodesk AutoCAD 2011 -64-bit-, 64-bit version, system requirements, 3D modeling, performance, legacy software, perpetual license.
Improved ability to import and work with large datasets from 3D scanners, a task that heavily benefits from 64-bit memory. System Requirements for 64-bit AutoCAD 2011