Another question, how much bandwidth do you want for this 20TB of data? With small factor storage directly attached to PCIe bus (M.2 discussed here, or older brother 2.5" U.2 NVMe) you have some balance between capacity and bandwidth. On the other hand, single SAS connector is not really that much, and there is no form factor with directly attached 3.5" PCIe bus.
Biting the hand that feeds IT
