I'm trying to do a large export - 310,000 jpegs (1920 pixels long edge @72dpi). When I click export nothing happens. tried smaller batches. Anyone know the maximum number of files I can export at one time?
There is no Max amount. You said you tried a smaller number of images. Did anything happen? How many images?
Try one or two images. Does it complete the export?
To what drive and folder have you selected as the export location? Does your User Name have Write access to that drive and folder?
An export of that size will take a considerable amount of time to first process and to complete.
Export operation can be very intensive and utilises lots of ram. Rending from raw original files will be time consuming and can take on average from 4 to 8 seconds for each file, depending the edits you may have done to the originals in the develop module. Things that take time are sharpening, noise reduction, lens correction, spot correction brushing etc.
Do the math trying to do all at once will take days and may even grind your computer to a halt depending on the memory and available disk space. Export is not just a simple copy process.
Best to try starting one export process with a couple hundred files then add a couple more and allow them to run simultaneously. As one finishes add another.