I presently have a 2009 mac pro 4.1 2.66GHz. 16MB ram. I primarily work with PS& LR often with large files 1-3 GB. I currently have my system & apps on a 240Gb sd drive; my files on other drives. It was suggested to get a 2nd ssd drive to use as a scratch disc. I have been looking at the OWC 240 GB ssd Accelsior S https://eshop.macsales.com/item/OWC/SSDACL6GE240/. My questions are 1. Should the scratch be on a ssd for faster operations? 2. what to put on the faster ssd, (accelsior S) , the system and applications or the scratch disk. ( I am guessing the system) 3. If I splurge to get the even faster Accelsior E2 800MB/s- will that actually make a big difference on my machine> https://eshop.macsales.com/item/OWC/SSDPHWE2R240/ Or is it overkill? Just tired of waiting for LR previews and PS operations. Thanks for your help.