G-Speed Shuttle XL T2 writing at no more than 600 MB/s

I have recently purchased a G-Speed Shuttle XL Thunderbolt 2 which is striped (raid 0) and hooked up to my Mac Pro. When I test the transfer speed it doesn’t exceed 600 to 650 MB/s. Is that normal since on the specs of the drive it says that its maximum speed is 1300 Mb/s? Anyone can help me please?

The Shuttle isn’t RAID0 out of the box. It is RAID5. If you want RAID0 you will need to delete the existing RAID5 using the software Utility and then remake a RAID0. Also the top speed is only based on the top capacity. The higher the capacity the faster it goes.