Thanks, Stephan,

I wonder how much onboard memory new cards need to handle 8000x8000. It looks like the Technote on GPUs and OpenGL has been revised. I don't see the information that I recall earlier about what features work with various amounts of onboard GPU memory. There are more specifics in the FAQ at the bottom of the technote:

< http://kb.adobe.com/selfservice/viewContent.do?externalId=kb 404898>

These are the FAQ's that seem most relevant to spec'ing a card:

Q. How much video RAM can Photoshop take advantage of?

A. Photoshop is limited by OpenGL itself on the amount of video RAM it can access. Photoshop can access approximately 500-700 MB of video RAM. 3D, a separate feature from OpenGL, allocates its own GPU resources, and can use as much video RAM as is on the display card. If you load a large 3D volumeric texture, for example, it might use a considerable amount of RAM (such as 1 GB) by itself, leaving less than expected for the rest of Photoshop.
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So if I'm working with a 3D layer in PS CS4 extended, it sounds like 1.7GB of memory would cover Photoshop's maximum memory utilization and the adapter's 3D rendering overhead.

Q. How much RAM do I need on my display card to run faster in Photoshop

CS4?
A. For basic OpenGL functionality, you should have at least 128 MB of RAM on your display card. If you're running Windows XP in general, OpenGL will work best if you have 256 MB RAM on your display card. Most Photoshop work will run faster with between 256 - 512 MB of display RAM. If you do a lot of 3D work, you use Panoramas or large images, or you need to have multiple applications open at the same time that use the GPU, you might benefit by having 512 MB or more RAM on the display card. <<

As I recall, the earlier version of this technote spelled out in more detail what "basic" OpenGL functionality means one image window without too much resolution in my experience.

The specific mention of XP suggests it needs more memory for OpenGL functionality. Vista virtualizes the graphics adapter and XP doesn't. I've yet to see anything but vague "it works better on Vista" from Adobe tech on what the GPU performance difference is between the two platforms.

Q. Does Photoshop take advantage of dual-GPU display cards?

A. Not at this time.
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SLI and Crossfire aren't utilized by Photoshop.

I guess I'll stand pat with the GTX 280 card. I wonder if running Aero features uses GPU memory.

alex_matu

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