Efficient display performance in Civil 3D is essential for maximizing productivity and minimizing frustrations. Following Windows, hardware, and AutoCAD performance best practices is essential to display optimization.
Operating System Optimization
Some operating system best practices can be followed to increase performance.
Optimize the Performance of Civil 3D in Windows
Follow Autodesk’s optimization guidelines to improve AutoCAD performance in Windows. Not all guidelines have the same effect on all systems, so test and compare results. Determine what provides the best results for your situation.
Optimizing AutoCAD performance in Windows
Excessive or corrupt AutoCAD temp files can cause performance issues. Delete temporary files regularly and clear the graphics cache.
How to delete temporary files in Windows
How to clear the graphics cache in AutoCAD Products
Hardware Optimization
Hardware configuration directly effects display optimization.
Hardware Acceleration
Hardware acceleration is a pivotal technique for bolstering graphics performance in CAD software. In Civil 3D, hardware acceleration utilizes the computer’s graphics processing unit (GPU) to offload certain tasks from the CPU, improving graphics performance and productivity, especially for 3D work and operations like zooming, panning, and rotating complex models.
While hardware acceleration is intended to be a benefit and deliver a performance boost, this may not always be the case. Machine architecture, video driver implementations, incompatible graphics cards, or virtual environments may cause the hardware acceleration setting to produce a negative effect or not work at all.
This feature can be enabled or disabled using the GRAPHICSCONFIG command. If you are experiencing display issues, try toggling hardware acceleration on and off to see if that resolves the problem.
How to enable or disable hardware acceleration in AutoCAD
Within the Graphics Performance dialog box, there are also 2D and 3D Display Settings. While these options improve the visual fidelity of the drawing, they can also impact performance, particularly on systems with less powerful hardware. Experimenting with turning these settings off can sometimes lead to noticeable improvements in responsiveness.
The DRAGP1 system variable controls the number of vector redraws during 2D drag operations with hardware acceleration. The initial value is 5000. Lower values might improve responsiveness for complex drags; experimentation advised.
Hardware Acceleration Not Working
If hardware acceleration does not seem to be working at all, here are some possible solutions.
Hardware acceleration cannot be enabled in AutoCAD products
Hardware Acceleration Troubleshooting Reference
Working with Older or Lower-End Video Cards
While it is ideal to run Civil 3D on a machine with Autodesk’s recommended system requirements, a lower spec’d machine may have to be used. Using older or low-end hardware will likely lead to display and performance issues.
Ensure the latest graphics card drivers are installed on the machine.
How to update to the latest certified video driver for Autodesk software
How to do a clean installation of a graphics card driver
Set specific application settings and Windows hardware configuration settings that affect display.
Improving AutoCAD performance with older or low-end graphics cards
(Depending on the amount of data being displayed, high-end graphics cards may benefit from these recommendations as well.)
Poor graphics performance with AutoCAD Products for Windows
How to use a previous DirectX version in AutoCAD Products
Civil 3D Application Optimization
Some Civil 3D settings can be tweaked to make the application more display friendly. Adopting all these settings will produce a performance boost, however experiment with the recommendations to find a balance between convenience and performance.
Visual Styles
Different visual styles in AutoCAD offer varying levels of detail and rendering complexity, which directly impacts the application’s performance. The 2D Wireframe visual style, which displays only lines and curves, generally requires the least amount of processing power and is recommended for working in complex areas of a drawing. In 3D models, the Shaded with Edges or Shaded visual styles are often preferred as they utilize the newer graphics engine in AutoCAD, which can provide better performance for 3D rendering.
Visual styles can be set with the VSCURRENT command and settings can be accessed with the VISUALSTYLES command.
Recommended System Variable Settings for Performance
DISPSILH 0
VSSILHEDGES 0
VSFACESTYLE 1 or 2
VSFACEOPACITY 100
VSHALOGAP 0
VSSILHWIDTH 1
Level of Detail
When working with intricate drawings that contain a substantial amount of detail, such as point clouds or highly tessellated three-dimensional models, managing the level of detail displayed in the viewport can significantly impact performance.
Recommended System Variable Settings for Performance
POINTCLOUDLOD Lower values (1-5) depending on the required visual detail
POINTCLOUDPOINTSIZE Increasing the size can improve performance at lower LODs
POINTCLOUDPOINTMAX Lower the limit based on system capabilities
Drawing Regeneration
Drawing regeneration (REGEN) is a fundamental process in AutoCAD where the software recalculates and redraws the objects in the viewport to accurately reflect any modifications made to the drawing. Automatic regenerations can occur during various operations, such as panning, zooming, or switching between layout tabs, and these can sometimes introduce delays, particularly in large and complex drawings.
Recommended System Variable Settings for Performance
LAYOUTREGENCTL 0 (for maximum performance once a tab is loaded)
2 (for a balance, regenerating each tab only once)
RTREGENAUTO 0 (Off) for very large drawings
Hatching
Displaying hatching can be a very resource intensive process.
Recommended System Variable Settings for Performance
Other Display Performance-Related System Variables
Several other AutoCAD system variables can have a notable impact on display performance and the overall responsiveness of the software. These variables often control aspects of the user interface.
Recommended System Variable Settings for Performance
CACHEMAXFILES 0 (to clear cache), otherwise a reasonable value (256)
BLOCKMRULIST 0
SELECTIONPREVIEW 0 (Off)
ROLLOVERTIPS 0 (Off)
TOOLTIPS 0 (Off)
DRAWORDERCTL 0 (Turns off default draw order)
PALETTEOPAQUE 1 (Opaque)
HIGHLIGHT 0 (Off)
ZOOMFACTOR Higher values (80-100)
Summary
In a previous post, we looked at best practices for the foundation for display optimization and increased performance. In this post we covered AutoCAD performance best practices, including setting optimal AutoCAD variables. Incorporating all these practices is essential and will produce immediate returns.
In a future post, we will look at workflow tips and tricks to minimize display issues and maximize performance.