The GPU Performance feature in the 2014 release of Illustrator CC enables rendering of Illustrator artwork on the graphics processor. GPU Preview is turned on by default for RGB documents on Windows 7 and 8 computers with compatible NVIDIA cards. You can also turn it on for CMYK documents by choosing Preferences > Experimental Feature tab. 

General considerations

• GPU Performance is not available on Mac OS.
• When GPU Performance is on, the View menu shows GPU Preview in addition to other preview modes. When GPU Performance is off, the View menu does not show GPU Preview.
• From GPU Preview, it is possible to switch to regular Preview, Outline, Pixel Preview, or Overprint Preview from the View menu. You can also use specific keyboard shortcuts.
• Preview, Outline, Pixel Preview, and Overprint Preview always use the CPU for rendering Illustrator art, whether GPU Performance is on or off.
• Toggle to Outline (Ctrl + Y) always brings back the last used preview (GPU Preview or CPU Preview).
• It is possible to toggle between GPU and CPU Preview, by using Ctrl + E.
• On Windows 7 & 8 computers with compatible NVIDIA graphics processors, the feature may not be available. (That is, Experimental Feature in Preferences panel is unavailable, or the indicator in Illustrator's menu bar is unavailable.) See the troubleshooting information to identify and resolve the issue.
• GPU Performance includes a new feature called Animated Zoom. You can turn it off, even while keeping GPU Performance on.
  
• In GPU Preview, if thin lines are faint or disappear, select the Enhance Thin Lines. Choose Preferences > Experimental Feature tab > GPU Performance.

Known issues

The following list is a set of known issues with GPU Performance:

• In CMYK documents, the appearance of objects with Blending Modes is incorrect in GPU Preview. [3718123]
• Images with CMYK spot colors are not rendered correctly in GPU Preview. [3719569]
• Blends created with an object containing effects may not render correctly in GPU Preview. [3719633]
• Objects with Photoshop effects are not rendered in GPU Preview. [3680844]
• Gradients and Gradient Meshes with Spot colors are rendered incorrectly in GPU Preview. [3715054]
• In CMYK documents, linked RGB images could show incorrect rendering in GPU Preview. [3720539]
• Rendering of colors could appear different in GPU Preview. [3705050]
• Thin strokes at low zoom levels may show a perceivable lag in rendering when Animated Zoom is stopped. [3736752]
• Redraw issues can appear while scrolling in Isolation mode with GPU Preview On. [3732193]
• Bitmap (1 bit) images can appear with a checkered appearance at 100% zoom in GPU Preview. [3684735]
• In GPU Preview, linked non-Photoshop EPS DCS file don't render correctly. [3718181]
• With document rulers ON, document's canvas can show a minor shift when toggling between GPU and CPU Preview. [3745431]
• Contents of a closed CPU-rendered document can appear momentarily when creating a document in GPU Preview. [3682701]
• While in GPU Preview, ruler origins may not update until the cursor is moved after release of click and drag. [3745463]
• In GPU Preview, Grid lines can appear anti-aliased. [3720002]
• When working with a Wacom Stylus, the origin of rotation/reflection cannot be repositioned in GPU Preview. [3710039]
• Non-native art with complex shadings does not get rendered in GPU Preview. [3726430]
• In GPU Preview, Live Corner widgets can display with a lag when the document is scrolled. [3715316]
• EPS files with gradients created in other applications and linked in Illustrator may render incorrectly in GPU Preview. [3708251]
• Drop shadows (with Darkness as the drop shadow option) applied to compound shapes at the Layer level may appear washed out in GPU Preview. [3680708]
• Simulate Colored Paper functionality works incorrectly in GPU Preview. [3715194]