


Photoshop will install both the 32-bit and 64-bit versions of Photoshop on 64-bit systems. Photoshop will automatically install the 32-bit version of Photoshop CS6 if you are on a 32-bit Windows OS. On Macintosh, only a 64-bit edition is available. On Windows, both Adobe Photoshop CS6 and Adobe Photoshop CS6 Extended have the option to run natively in either 32-bit or 64-bit editions. Speed is more important for my general photography, so I configure the 64 bit Photoshop for less display quality, more speed.For detailed instructions on installation, visit the installation page. In the former case, I open images through a 32 bit plug-in called FITS Liberator, and it's more important that while editing the document preview is composited with more accuracy, so I configure it for Cache Levels 1. For me this affords me the opportunity to easily start the 32 bit version to work on astroimages and the 64 bit version to work on general photography.

I personally like the fact that they can be configured differently for most things and they remember their own configurations. This isn't really a "show stopper" issue, though, since Photoshop offers several backup plans (OpenGL, CPU execution). It's rare to have that be the case, but I can think of one thing right now: I can only see OpenCL capability in 64 bits. You may find your display driver does some things better in 64 bit and others better in 32 bit.

Seriously, 32 bit Photoshop provides you the ability to install and run older 32 bit only plug-ins.
