My export rate on current pics (in the 5600 x 3200 range) is between 3 and 7 a minute. This is with minimal adjustments and a crop, similar performance with camera raw files or jpegs.
If I go back to pics from my archive (around 2700 x 1500) I can export over 100/min from jpg, about 50/min from raw.
All tested with the same export settings, couple of times both with and without a resize.
I understand that the bigger pictures require more processing but the difference in processing time seems exceptionally high.
I've tried every optimization tip I can find too, no discernible difference.
I have older i7 with ssd, gpu. It's obviously capable of processing the smaller files quickly.
Am I missing something or anyone got any tips beyond the usual stuff?
It would be helpful if you provided details on the hardware (computer specification) and operating system you're using
One consideration: a 5600 x 3200 pixel image has 4.4 times as many pixels as a 2700 x 1500 image. The time for export is to a large degree dependent on the number of pixels, so you might expect export to go 4.4 times slower with the larger pics. You're observing about a 10x slowth (50/min / 5/min), and thus about half of that could be accounted for by the increase in pixel size alone. (This is all back-of-the-envelope, of course.)