Keep the Properties and Layer palettes closed when not actively in use to free up system resources. System requirements for AutoCAD 2012 - Autodesk
Even on a 64-bit system, you can make AutoCAD 2012 even "better" by following these expert performance tips from AUGI Forums : autocad 2012 portable windows 7 64 bits better
Using the 64-bit version on Windows 7 allows the software to access significantly more RAM (the recommended 4GB–8GB) than the 3GB limit of 32-bit systems, preventing crashes during complex renders. Keep the Properties and Layer palettes closed when
A "portable" version is one that runs without a formal installation process. This is often preferred for several reasons: This is often preferred for several reasons: You
You can run the application directly from a USB drive on any Windows 7 machine without needing administrative privileges for installation.
To get the "better" experience you're looking for, ensure your Windows 7 64-bit system meets these official Autodesk System Requirements : Minimum Requirement Recommended for 3D/Large Files AMD Athlon 64 or Intel Pentium 4 (with SSE2) 3.0 GHz or higher dual-core RAM 4 GB to 8 GB Disk Space 2 GB (portable versions typically need less) 6 GB for full installs Display 1024 x 768 True Color 1600 x 1050 True Color GPU Direct3D®-capable card 128 MB or greater with Pixel Shader 3.0 Tips to Improve AutoCAD 2012 Performance