I've been using LR 5 for years now, & finally upgraded to a iMac, and am using the updated LR. When you are working on editing your RAW files, such as Wedding photos for example, do you download them all into lightroom, then save them on an external harddrive? OR do you have a "working external harddrive" and use that to edit in and out of so you arent bogging down the performance of the mac. Any suggestions or opinions are welcome! 🙂 Thanks.
The problem with external drives is that they are vulnerable to file corruption because of unreliable connectors. It doesn't take much jiggling of a USB cable before the connection breaks for a microsecond. It's happened to me. An internal drive has a much steadier connection (as well as being much faster).
Getting your raw files off the memory card is a vulnerable point for the same reason. Lots of corruption happens at this stage.
But basically, you'll want to work off local drives as much as possible. External drives are for storage and retrieval. IMO this is one of the main advantages of desktop systems: you can just cram in as much disk space as you like. I currently have 25 terabytes in my machine.