With a computer that's ancient by today's standards -- single proc/single core, Win XP SP2, only 1 GB of RAM -- I can't expect high performance from any graphics-related apps (can't run CS4 at all -- it freezes not long after launch; have to use CS2 instead; can't even consider CS5 yet). That aside, I get reasonable conversion times with an older version of Lightroom -- about 20-25 seconds per RAW file.
Recently I downloaded and installed Lightroom v.3 beta 2 and did my first conversions with it last night. Big difference in performance -- roughly sixty seconds per file.
But could this have been a factor: for the first time I decided to try a DNG-only workflow to see how that would go. I started with about 20 RAW files and converted them to DNG (no compression, largest possible preview sizes, non-linear output).
It took a while to figure out that permanently storing edit settings within the DNG files themselves requires using Lightroom's "save to files" menu item -- otherwise, a file removed from the LR catalogue and imported again later won't retain its settings. Not having to use sidecar files seems -- at least in theory -- like a convenience. But the manual "save" is not so convenient. (If there's a way of also using .XMP sidecars with DNG files, I haven't found it yet. "Save to files" never seems to produce XMP files with these DNGs.) So, two questions:
Is there a way in LR 3 to have edit parameters saved within the DNG files, and have embedded previews updated in the background/on the fly, automatically -- not manually? (Refreshing/updating the DNG previews took a LOT longer than the "save to files" operation. But it was necessary if I wanted an accurate rendition of the updated images within, say, Photo Mechanic.)
Could the use of DNG format by itself have made any difference in performance during the export-to-TIFF operation? Or is output speed simply known to be lower in Lightroom 3 compared with earlier versions?