To run AutoCAD Civil 3D 2018.1.1 smoothly, your system should meet or exceed these official specifications : System requirements for AutoCAD Civil 3D 2018 - Autodesk

: Added "Zoom to Section View" and "Zoom to Sample Line" functionality for quicker navigation between detailed sections and their locations on the main alignment. 1.1 Update Enhancements & Performance

: Provides greater control over layer overrides in external references, allowing you to specify which properties to reload via the Layer Settings dialog.

AutoCAD Civil 3D 2018.1.1: A Comprehensive Guide to New Features and Enhancements

: New commands to easily create and place model views onto layouts with automatically sized viewports. System Requirements for Optimal Performance

: Significant boosts in "Wireframe," "Realistic," and "Shaded" visual styles, with some benchmarks showing a 37% increase in frames-per-second over the initial release.

: Over 200 dialog boxes and UI elements have been updated to scale correctly on 4K monitors.

The "1.1" specific update applies broad improvements across all AutoCAD-based products, including:

: Includes new net-based rehab subassemblies and a dedicated CreateRehabCorridor command to manage roadway resurfacing and leveling projects more efficiently.