With version 2.0, Apple has done a substantial re-write of Aperture's underlying database. This should make many searching functions much faster, as Aperture can now process your image database more efficiently. For more everyday work, Aperture 2.0 provides a new command that can give you dramatically improved performance.

When you activate the new Quick Preview option, Aperture displays previews much more quickly. In Quick Preview mode, Aperture stops generating new previews and uses whatever JPEG file it can find. Sometimes, this might be a preview that Aperture previously generated. With newly imported images, it will most likely be the low-res preview JPEG that your camera generated for display on its own LCD screen.

To activate Quick Preview mode, just press P, or click the Quick Preview button that sits just above the Browser pane.

When Quick Preview is on, the button will highlight, and you should see a noticeable speed boost when Aperture displays previews.

Bear in mind that these previews are not always accurate - they won't necessarily show your most recent adjustments. If you're working with raw files, there might be color and contrast differences when in Quick Preview mode, because these previews might not have been generated by Aperture's raw converter.

At any time, you can press P again to leave Quick Preview mode. The currently selected preview will be updated to show your current raw converter and adjustment settings.