In theory, there should be a difference (300 MB/s vs. 600 MB/s). https://en.wikipedia.org/wiki/Serial_ATA#3.0
Can't say anything about Syria. After the Normandy map I didn't feel the need for another map from Ugra Media. Maybe increasing the preload-radius could help. Don't think SATA is your problem, but I don't know what your hardware consists of.