Notes:
8GB = approximately 6GB~7GB
16GB = approximately 14GB-15GB
32GB = approximately 28GB-30GB
64GB = approximately 58GB-60GB
128GB = approximately 110GB-120GB
256GB = approximately 230GB-240GB
512GB = approximately 460GB~476.6GB
1TB = approximately 900GB~950GB
2TB = approximately 1700GB~1862GB