The Photoshop CS5 Upgrade (Introduction)
This series on Photoshop CS5 will grow over time, but for starters we’ll focus on speed vs Photoshop CS4.
The 64-bit gain
The key difference between Photoshop CS4 and CS5 is that CS5 now uses Apple’s Cocoa framework for the user interface, allowing CS5 to be a full 64-bit application. This is what Adobe says caused it so much work and delay; rewriting the user interface from Carbon to Cocoa.
Of course, Photoshop CS5 has cool new features and capabilities, but for those working with large files, the 64-bit thing is key, because it means that working with large files can be much faster, because operations can be performed in memory.
You can observe memory usage using Activity Monitor.
After running the diglloydMedium Benchmark, Photoshop CS5 is using 14.67GB of real memory, with 89 threads created (on an 8-core Mac Pro Nehalem). The “Intel (64 bit)” kind confirms it as 64-bit, though obviously it has to be to use 14+ GB of real memory.