How striping splits your data
RAID 0 cuts data into chunks and deals them out to the drives in turn, the way you'd deal cards. A big file ends up spread over every drive, so each drive reads or writes its share at the same time. It needs at least two drives, and every byte of raw space is usable. Two 2 TB drives give 4 TB, or 3.6 TiB in binary units.
The speed gain is real but smaller than the theory. In the best case the array runs at the sum of its drives on big sequential transfers. Small random reads and writes gain less, and some workloads don't speed up at all. Striping can't turn slow drives into fast ones either. A single PCIe 4.0 NVMe drive reads 13 times as fast as a SATA SSD in the model the Throughput Visualizer uses, so two SATA SSDs in RAID 0 still fall short of it.
The failure odds add up
Every drive in the stripe is a single point of failure. Lose one and the data on the others is useless, because each file is missing a piece. There's no degraded mode and no rebuild. You restore from backup.
The odds grow with the drive count. At a planning rate of 2% a year per drive, the chance that at least one drive fails within a year is 2% for one drive, 4% for two, 8% for four and 15% for eight. Two percent is an assumption, not a spec. Backblaze reported a 1.36% annualized failure rate for its drives in 2025, and a 2007 study of about 100,000 disks found yearly replacement rates of 2-4% common. That study also found that replacements cluster in time, so a flat yearly rate doesn't tell the whole story.
Where RAID 0 still makes sense
Use it for data you can recreate: a video editing scratch disk, a render cache, a game library you can download again. Keep it away from anything unique. A boot drive in RAID 0 puts the whole operating system and your files into one failure domain.
Before you build one, check what a single drive does. A modern NVMe drive on its own often beats an older SATA stripe, as the model above shows, and it adds no extra point of failure. Striping fast NVMe drives can still pay off for scratch work that needs more than one drive can give.