Native 64-Bit OS Support
The proverbial big kahuna of After Effects CS5 is certainly its behind-the-scenes architecture upgrade. There's a good deal of confusion about what it means for the app to be 64-bit, since previous releases had included, for example, the upgrade to a 32-bit per channel (HDR) image pipeline. The CS5 64-bit change is an otherwise invisible upgrade to the application that allows it to use more of your system's physical memory (RAM)and to do so more intelligently.
Like any sweeping change, this one brings along other incidental improvements that have made CS5 a much faster application, even if your system doesn't have the resources to take full advantage of the increased memory overhead. Because the developers had to rewrite major sections of code in core areas of After Effects, features related to those areasincluding such fundamentals as the color pipeline and pixel transformswere optimized, more or less for free. It's kind of like this: If you remodel your house, you might also take advantage of the chance to put in a new climate system and upgrade the furniture.
The benefits are pretty huge. Errors having to do with the application being out of memory, which had become increasingly prevalent in the era of HD and beyond, are all but gone. RAM previews can become astonishingly longer when they can use all of a double-digit gigabyte amount of physical memory. And multiprocessing, which was always a roll of the dice at best in After Effects, now just worksit reliably uses your multiple processor cores to render faster.
The best part is that there's very little to manage. After Effects actually runs best when you leave a couple of processor cores and a few gigabytes available to other applications, assuming that you're on a system with eight or more processors and a couple gigabytes of RAM per processor (see Figure 3). If you're not on such a system, you now have more reason to upgrade, because the application will take greater advantage of anything you can give it.
Figure 3 Optimal settings leave processors and memory available to applications outside those whose icons appear in this panel.