Curious as to what parts of the Adobe Creative Suite 4 (CS4) are accelerated via offloading processing onto the GPU? Here is what to expect, with a few video examples...
GPU processing of page display zooming, panning of PDF through OpenGL drawing.
Smooth (animated) zooming, even at non-standard zoom levels. Smoother rotation of large images. Hardware accelerated pixel grids. GPU color conversion. GPU-based brush drawing.
Preview and display of images is accelerated through OpenGL drawing. Slideshows and reviews can now display effects quicker.
3D depth of field controls, blending modes, adjustment laters, effects, anti-aliasing, motion blurs, lights, and shadows can be offloaded onto GPU for faster performance.
Video playback speedup through GPU offloading. GPU acceleration in Flash also lays the ground work of true 3D in Flash, although it's yet to be truly exploited.
Page curl, refraction, and ripple effects accelerated via GPU. GPU based output rendering/encoding with RapiHD H.264 plugin (up to 10x speed boost).
As you can see, a lot of applications see enhancements and speedups through GPU offloading, although it's definitely not across the board with the CS4 suite, and we're only seeing the GPU interact with bits and pieces at this point. This is more or less laying a foundation for future releases to use the GPU more frequently, and I'm sure in the CS5 suite we'll see more features being offloaded onto the GPU or being built for the GPU from the get-go.
Adobe After Effects CS4 with GPU Acceleration
One thing to note is that Adobe's CS4 GPU acceleration support is not limited to the QuadroCX card. Any system with a modern GPU (DX9+ level) with OPenGL support should be able to enable these features and see enhanced performance. However, the Premiere Pro GPU media encoding functionality is limited to the QuadroCX only at this time.
In terms of our real-world experience, here's how it goes. As heavy Photoshop users and a photographers who shoots primarily in RAW at 4000px+ resolutions, the GPU acceleration effects in Adobe Bridge were immediately noticeable and definitely helped the smoothness of our system. As for GPU acceleration in Photoshop CS4, it really does seem to be hit or miss. Some aspects of the software seem quicker with GPU acceleration, although some areas tend to actually lag a bit more with it enabled. We should also note that the number of open, OpenGL accelerated documents is limited by available frame buffer memory. For example, with a 1GB GeForce GTX 280, 18 OpenGL accelerated documents can be open at one time.
Adobe Photoshop CS4 with GPU Acceleration
If you're already running on a fast system, a fast dual-core or a quad-core, you're not going to see that big of a performance boost. If you're on a slower system, offloading onto the GPU will definitely help, especially when dealing with large files. It is not a huge cure-all for slow Photoshop performance, but it can come in handy at times.