FAQ: What features use the GPU and how do I troubleshoot GPU issues?

Question

Photoshop CS6 GPU FAQ
Introduction
This document provides a quick reference guide to video card usage in Photoshop.  Some features require a compatible video card to work; if the video card or its driver is defective or unsupported, those features will not work at all.  Other features use the video card for acceleration and if the card or driver is defective those features will run more slowly.
Mercury Graphics Engine
The Mercury Graphics Engine (MGE) represents features that use video card, or GPU, acceleration. In Photoshop CS6, this new engine delivers near-instant results when editing with key tools such as Liquify, Warp, Lighting Effects and the Oil Paint filter. The new MGE delivers unprecedented responsiveness for a fluid feel as you work.
MGE is new to Photoshop CS6, and uses both the OpenGL and OpenCL frameworks. It does not use the proprietary CUDA framework from nVidia.
In order to use MGE, you must have a supported video card and updated driver. If you do not have a supported card, performance will be degraded. In most cases the acceleration is lost and the feature runs in the normal CPU mode. However, there are some features that will not work without a supported video card.
GPU features added in Photoshop CS6
Adaptive Wide Angle Filter (compatible video card required)
Liquify (accelerated by compatible video card with 512MB VRAM, GPU mode unavailable on Windows XP)
Oil Paint (compatible video card required)
Warp and Puppet Warp (accelerated by compatible video card, GPU mode unavailable on Windows XP)
Field Blur, Iris Blur, and Tilt/Shift (accelerated by compatible video
card supporting OpenCL, GPU mode unavailable on Windows XP)
Lighting Effects Gallery (compatible video card required with 512MB
VRAM, unavailable on Windows XP)
New 3D enhancements (3D features in Photoshop require a compatible video card with 512MB VRAM, unavailable on Windows XP):
Draggable Shadows
Ground plane reflections
Roughness
On-canvas UI controls
Ground plane
Liqht widgets on edge of canvas
IBL (image based light) controller
* Note that all 3D features are unavailable on Windows XP in Photoshop CS6
GPU features added in previous versions of Photoshop
Scrubby Zoom. See Zoom continuously
Heads Up Display (HUD) color picker. See Choose a color while painting
Color sampling ring. Choose colors with the Eyedropper tool
Brush dynamic resize and hardness control. See Resize or change hardness of cursors by dragging
Bristle Brush tip previews. Bristle tip shape options
Rule of thirds crop grid overlay. Crop images
Zoom enhancements. Smooth display at all zoom levels and temporary zoom. See Zoom continuouslyTemporarily zoom an image
Animated transitions for one-stop zoom.
Flick-panning.
Rotate the canvas. Use the Rotate View tool
View nonsquare pixel images. Adjust pixel aspect ratio
Pixel grid. Hide the pixel grid
Adobe Color Engine (ACE).
Draw Brush tip cursors. Resize or change hardness of cursors by dragging
Adobe Bridge GPU features
Preview panel
Full-screen preview
Review mode
See Preview and compare images in Adobe Bridge CS6 Help for information on all of these features.
GPU/OpenGL preferences in Photoshop CS6
The advantages of using a compatible video card (GPU) with Photoshop are that you can experience better performance and more features.   Problems can occur if you have an older video card with limited VRAM or if you use other programs at the same time as Photoshop that use the GPU.
Choose Edit > Preferences (Windows) or Photoshop > Preferences (Mac OS).
In the Performance panel, make sure Use Graphics Processor is selected in GPU Settings.
Click Advanced Settings and specify the following options:
Mode > Basic
Mode > Normal
Mode > Advanced Provides the benefits of Normal mode as well as newer OpenGL advances that can result in improved performance.
Use Graphics Processor to Accelerate Computation
Use OpenCL Uses the GPU to accelerate the new blur filters (Field Blur, Iris Blur, and Tilt-Shift) – OpenCL will only be available on newer GPUs that support OpenCL v1.1 or higher
Anti-Alias Guides And Paths Allows the GPU hardware to smooth the edges of drawn guides and paths.
30 Bit Display (Windows only) Allows Photoshop to display 30 bit data directly to screen on video cards that support it
Quick GPU Troubleshooting Steps
You can experience problems such as artifacts, errors, and crashes if there are incompatibilities between Photoshop and the display components that access the GPU.
If you experience crashes, incorrectly rendered windows or objects, redraw issues, or performance issues while running Photoshop, first determine whether OpenGL is causing the problem.
Turn off OpenGL.
Choose Edit > Preferences (Windows) or Photoshop > Preferences (Mac OS).
In the Performance panel, uncheck Use Graphics Processor. Click OK.
Restart Photoshop, and perform the same function.
If the problem recurs while OpenGL Drawing is disabled, OpenGL is not the cause. For additional troubleshooting, see Troubleshoot system errors and freezes | Adobe software on Windows (cpsid_82252) or Troubleshoot system errors and freezes | Adobe software on Mac OS 10.x (cpsid_82414).
If the problem resolves, proceed with the rest of the troubleshooting steps to fix OpenGL.
Make sure that you're using the latest update of Photoshop.Updates fix bugs and issues.
Update the display driver.Updated display drivers can fix many issues, such as crashing, incorrectly rendered objects, and performance problems. Determine what video card you have and go directly to the manufacturer's website (nVidia or ATI/AMD) and download the latest driver. (Note: Simply doing a Windows Update is does not guarantee you are using the latest driver. You must go directly to the nVideo or ATI/AMD websites to get the absolute latest driver.) After you update your driver, turn on Use Graphics Processor in Photoshop preferences.
Reset preferences.
Resetting preferences returns OpenGL settings to their default status. Reset Photoshop preferences by pressing and holding Shift+Ctrl+Alt (Windows) or Shift+Option+Command (Mac OS) immediately after you start Photoshop.
Click Yes when asked if you want to delete the Adobe Photoshop Settings File.
Retry the function that caused the problem.
Change the OpenGL mode to Basic.
Setting the OpenGL mode to Basic uses the least amount of GPU memory and the most basic GPU feature set.
Close all documents.
Choose Edit > Preferences (Windows) or Photoshop > Preferences (Mac OS)
In the Performance panel, click the GPU Settings Advanced Settings button.
Choose Mode > Basic
Restart Photoshop.
If this solution resolves the problem, switch to Normal mode. See if the issue recurs. If the issue recurs, return to Basic mode.
Note:  If you’re changing GPU preferences to troubleshoot a problem, re-launch Photoshop after each change.
If you are using more than one video adapter, remove the additional cards.
Multiple video adapters can cause problems with GPU accelerated or enabled features in Photoshop. It's best to connect two (or more) monitors into one video adapter. If you have to use more than one video adapter, make sure that they are the same make and model. Otherwise, crashes and other problems can occur in Photoshop.
Note: Using two video adapters does not enhance Photoshop's performance.
Check your Cache Levels setting.
If you've set your Cache Levels to 1 in Photoshop preferences, you can experience performance issues with GPU features. Reset Cache Levels to the default setting, which is 4.
Choose Edit > Preferences > Performance (Windows) or Photoshop > Preferences (Mac OS)
In the Performance panel, choose Cache Levels > 4.
The GPU Sniffer
To help guard against Photoshop crashes related to bad GPU hardware or drivers, Photoshop employs a small program called the GPU Sniffer. Every time Photoshop is launched, Photoshop launches the sniffer. The sniffer runs rudimentary tests of the GPU and reports the results to Photoshop. If the sniffer crashes or reports a failure status to Photoshop, Photoshop will not use the GPU. The Use Graphics Hardware checkbox in the Performance panel of the Preferences will be unchecked and disabled.
The first time the sniffer fails, Photoshop will display a dialog indicating that it has detected a problem with the GPU. On subsequent launches the dialog will not appear unless the Photoshop preferences are reset.
If the user corrects the problem, either by replacing the video card or by updating the driver, then the sniffer will pass on the next launch and the Use Graphics Hardware checkbox will be enabled and returned to its previous state (enabled or disabled).
Tested video cards for Photoshop CS6
Adobe tested the following video cards before the release of Photoshop CS6. This document lists the video card by series. While the minimum amount of VRAM supported on video cards for Photoshop CS6 is 256MB, some features require 512MB of VRAM to be enabled.
Note: Adobe tested laptop and desktop versions of the following cards. Be sure to download the latest driver for your specific model. (Laptop and desktop versions have slightly different names.)
nVidia GeForce 8000, 9000, 100, 200, 300, 400, 500 series 
nVidia Quadro 400, 600, 2000, 4000 (Mac & Win), CX, 5000, 6000
AMD/ATI Radeon 2000, 3000, 4000, 5000, 6000, 7000 series
AMD/ATI FirePro 3800, 4800, 5800, 7800, 8800, 9800, 3900, 4900, 5900, 7900
Intel Intel HD Graphics, Intel HD Graphics P3000, Intel HD Graphics P4000
Note: ATI X1000 series and nVidia 7000 series cards are no longer being tested and are not officially supported in CS6 – some basic GL functionality may be available for both these cards.
Note: 3Dand some Open GL features are disabled on Windows XP, as stated on : http://labs.adobe.com/technologies/photoshopcs6/

Answer 1

I've had several timeout since the pings were started. Got a some response times > 1ms (nothing greater than 7 or 8ms), but no timeouts.