RAID 0 with two 2 TB drives: speed, capacity, and the zero-redundancy gamble

How this is calculated

RAID 0 multiplies failure risk. A single drive might have a 2% annual failure rate. Two drives in RAID 0 have a combined ~4% annual chance of array loss, assuming independent failures. In practice, drives bought at the same time from the same batch tend to fail around the same time, making the real-world risk slightly higher. The speed benefit is real for sequential workloads like video editing scratch disks and large file transfers. For random I/O (boot drives, game libraries), the real-world speedup is much smaller, typically 20-40% rather than the theoretical 2×.

Verdict

The math is concrete: two 2 TB drives stripe to 4 TB usable at roughly double single-drive sequential throughput, but the failure probability multiplies, not averages. With a 2% annual failure rate per drive, the array faces roughly a 4% annual loss risk, and that risk is higher in practice because drives from the same batch tend to fail together, which is the same-batch failure mode that haunts RAID 5 rebuilds. The workload-win is real for sequential transfers (video scratch disks, large-asset copies) but smaller than the marketing suggests: random I/O on a RAID 0 array of SATA SSDs typically lands 20-40% faster than a single drive, not 2x. A single modern NVMe drive at 5,000-7,000 MB/s will outclass any SATA RAID 0 array for the same use case, which is why RAID 0 now lives almost entirely on replaceable-data workloads.