I do a lot of lightroom work on batches of about 1000 images at a time. My late 2011 iMac is maxed out with RAM (16gb), and the processor is a 3.1 go intel core i5. I'm storing my catalogs and files on external USB 3 drives just because of the sheer volume of files is impractical to store on the internal drive. I'd do striped RAID's but their insecurity scares me. My system can't keep up with the speed I work. I fond myself waiting for lightroom to "think" for small bits of time when I'm working that even though they are small "stutters" they add up to a significant slowdown because of the volume of work I do.
It is time for me to upgrade. I've been told a Mac Pro is overkill and that seems to make sense to me, I don't do a ton of video (although I do do a decent amount, none is 4K). But if someone convinced me otherwise it's in the budget. I'm thinking an iMac 27 inch retina is the right fit. But I'm still confused as to which computer element has the greatest affect on Lightroom performance? I don't care about export speed. I want responsiveness when I'm working in the develop module. No stuttering.
Is a fast processor the most important thing?
Is RAM the most important?
Would a few external SSD's to work off of speed things up significantly?
Is there some kind of system of storing previews on the internal drive and keeping the RAW files on external drives that speeds up workflow?
Any help would be greatly appreciated!