Customize menu > Preferences > Preference Settings dialog > Viewports tab > Display Drivers group > Configure Driver button (when HEIDI is the current driver)
The HEIDI display driver does not require hardware acceleration.
Interface
Redraw Scene On Window Expose: Redraws the whole scene when a dialog over the viewports is moved, resulting in smoother dragging of dialogs such as the Material Editor or Track View.
If your gmax display easily becomes messy or "corrupted," turn this option on and then redraw viewports by choosing Views > Redraw All Views (the default keyboard shortcut for this is the "1" key).
Use Triangle Strips: "Stripifies" the geometry, which can more than double the display speed. In some cases, such as when topology is constantly changed, the time taken to stripify the geometry can cause a slowdown instead. In such cases, turn off this option. Otherwise, leave it on for speed.
Download Texture Size group
64, 128, 256, 512: These buttons specify the size of the bitmaps used to map surfaces in the viewports. The larger the size, the better the resolution but the slower the speed. High speed produces jagged maps and slower speeds produce smooth maps.
Note: When Match Bitmap Size As Closely as Possible is on, these buttons are overrided, however they are still available. The value is still used when procedural textures are converted to bitmaps for viewport texture display.
Match Bitmap Size as Closely as Possible: To allow the viewport to show actual texture resolutions, bitmaps are individually resized in the display. This means that small bitmaps donÆt get overexpanded and large bitmaps retain their resolution (but potentially use a lot more video RAM).
Note: Bitmaps can be no larger than 4000 x 4000 pixels (or they will be scaled down to this size) and no smaller than 32 x 32 (or they will be scaled up to this size). Default=off.