I have a 2013 Mac Pro and Photoshop is using upwards of 300GB of scratch space at the moment on a couple of jobs i'm doing. I can't delete anymore files and still keep running out of space. I know OWC sell a 4TB blade for this machine but its a fair bit slower and i want to keep the speed i have on this internal SSD. Is there a thunderbolt alternative i can put a sm951 in and get similar to the internal speeds of the current SSD i have installed? I've seen the Sonnet Fusion PCIe Flash Drive - 512GB but a price tag of £650+Vat seems a bit steep! Any alternatives?