Having a large memory count with a 64 bit operating system means that you can allocate more to Adobe Photoshop. While this will make little difference when opening small files, it can play a part in increasing performance with larger, more demanding media.
Above: Memory available to Photoshop CS5 with 6GB installed (5311MB).
Above, the ‘performance’ subpanel of the main preferences pane. Here you can allocate the amount of memory you have available to Photoshop. 32 bit operating system and versions of this program are limited so we recommend the 64 bit platform for ultimate performance and memory availability.
Above: Memory available to Photoshop CS5 with 12GB installed (10913MB).
With 12GB of memory installed you have significantly more memory available to the program. This means that you can open larger (or more) files before Photoshop forces data into the application scratch disk.
We increased the memory count with both configurations, leaving a little for the system. (9,000MB for 12GB system and 4,000MB for 6GB system).
First we opened a large rendered image, and resized it to 45,000 x 54,864 pixels, creating a final image of 6.9gb in size.
With 9,000MB of memory available to Photoshop the scratch disc is never accessed, saving 5 seconds of conversion time when compared to the settings with 6GB of system memory available.
Next we changed the colour mode to CMYK, mirroring a common task required by a printing agency or newspaper. This increases the file size to 9.20GB.
With 9,000MB of memory available it took 58 seconds to complete the task. With 4,000MB of memory accessible this increased to 88 seconds. Substantial performance improvements.