Running Photoshop in 64-bit mode produces some big improvements when using large data sets (scenarios where you’d otherwise run out of RAM and have to hit virtual memory). Here are benchmarks from a 2 x 2.66GHz quad-core Nehalem Mac Pro with 12GB of RAM (OS X 10.6.3):
Running the Retouch Artists Speed Test:
CS4: 36.09 secs
CS5 64bit: 14.78 secs
2.4 times faster*
Running the diglloyd benchmark Actions for Photoshop:
diglloydSpeed1
CS4: 38.05 secs
CS5: 23.1 secs
1.7 times faster
diglloydSmall
CS4: 56.01 secs
CS5: 26.48 secs
2.1 times faster
diglloydMedium
CS4: 120.15 secs
CS5: 83.85 secs
1.4 times faster
Opening a large (3.75GB) PSB file
CS4: 80.33 secs
CS5: 52.43 secs
1.5 times faster
Obviously these are big, big wins for any Photoshop users working with large images. I do however want to be careful not to oversell the benefits of 64-bit. As I’ve said from the start, 64-bit is a really big deal when you’re using large amounts of memory. Otherwise it’s not likely to make a very noticeable difference (e.g. your Web design tasks won’t run twice as fast).
What about other Creative Suite apps? As I’ve mentioned, After Effects & Premiere Pro are both 64-bit native on both Mac & Windows (64-bit only, in fact, unlike Photoshop). I haven’t seen benchmarks yet, but given the data-intensive nature of video, the wins should be huge. Meanwhile Illustrator has raised the limits on RAM usage, from 2GB in CS4 to 3-4GB (depending on system configuration) in CS5.
* I’m using the same “times faster” nomenclature that Apple uses when talking about 64-bit performance on Snow Leopard. If you prefer to think in percentages, the operations are (from top to bottom above) 59%, 39%, 53%, 30%, 35% faster than CS4, respectively.