As you've probably seen, among the great features in the Lightroom 2.0 beta is its ability to run 64-bit-native on Mac (Intel, 10.5.x) and Windows (Vista 64). If you think it feels great to beat Aperture to the punch here, you're right. 🙂
What does 64-bit computing mean, practically speaking? In a nutshell, it lets an application address very large amounts of memory--specifically, more than 4 gigabytes. This is great for pro photographers with large collections of high-res images: Lightroom being able to address more RAM means less time swapping images into and out of memory during image processing-intensive operations.
It's also important to say what 64-bit doesn't mean. It doesn't make applications somehow run twice as fast. As Photoshop architect Scott Byer writes, "64-bit applications don't magically get faster access to memory, or any of the other key things that would help most applications perform better." In our testing, when an app isn't using a large data set (one that would otherwise require memory swapping), the speedup due to running in 64-bit mode is around 8-12%.
Therefore 64-bit is a good thing for Lightroom now, and as the amount of data photographers handle inexorably grows, it'll become a bigger win.
The Lightroom news naturally raises the question: What's Adobe doing with Photoshop? In the interest of giving customers guidance as early as possible, we have some news to share on this point: in addition to offering 32-bit-native versions for Mac OS X and 32-bit Windows, just as we do today, we plan to ship the next version of Photoshop as 64-bit-native for Windows 64-bit OSes only.
The development is frankly bittersweet for us: On the one hand we're delighted to be breaking new ground with Photoshop, and when processing very large files on a suitably equipped machine, Photoshop x64 realizes some big performance gains. (For example, opening a 3.75 gigapixel image on a 4-core machine with 32GB RAM is about 10x faster.) On the other hand, we work very hard at maintaining parity across platforms, and it's a drag that the Mac x64 revision will take longer to deliver. We will get there, but not in CS4. (Our goal is to ship a 64-bit Mac version with Photoshop CS5, but we’ll be better able to assess that goal as we get farther along in the development process.)
Adobe, PhotoShop, Photoshop CS4, Photoshop CS5, Lightroom, Adobe Lightroom, Beta, Roadmap, Time Table, Windows Vista