Another problem when comparing export timings is getting to an apples vs apples comparison. CPU power is but one factor, other factors include: 1. Size of input file, obviously....the bigger the file, the longer it's likely to take to export. 2. The size of the output file, specifically the pixel dimensions. Reducing the pixel size of the export file is initially likely to see a speedier export, but there comes a point whereby really small export file sizes start to take longer to export than full-size exports. 3. The export quality setting (assuming a Jpeg export), a reduced quality has some small beneficial effect at full-size, but that disappears as you reduce the output size. 4. Develop edits.....the number and type of develop edits can also significantly increase export time. Some have little effect (white balance, exposure, contrast, saturation), whereas others (vibrance, clarity etc.) require a bit more work. 5. The I/O sub-system....goes without saying a really fast sub-system is needed to keep all those CPU cores busy. On my system that's certainly my bottleneck, exports of standard unedited 21mp files from the 5dII take about 4 secs each. Never thought of that as being slow, though no doubt I could improve a little with SSDs. Here's a graph of some export timings I did last year using LR3. Used 35 unedited files for most of the tests, but also ran one test on 35 edited files, the difference is apparent. Whatever settings you were using, I personally would be very happy with a 2 seconds per image export time.....the vast majority of Lightroom users would be very, very envious.
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