The cheapest path to 100TB at home

A hundred terabytes sounds like a datacenter number, but for a media hoarder, a self-hoster or anyone with a few cameras and a long memory, it’s an ordinary target now. The question isn’t whether you can reach 100 TB at home — it’s how to do it for the least money once you count everything, not just the drives. Here are the strategies that actually move the needle, roughly in order of how much they cut your bill.

1. Used enterprise drives: the biggest lever

Retired datacenter drives are the single most effective way to crush your $/TB. Datacenters cycle out hardware on fixed schedules regardless of remaining life, flooding the secondary market with large, still-healthy disks. A stack of used enterprise SAS or SATA drives routinely lands well below new consumer pricing per terabyte. The catch: SAS drives need a SAS host bus adapter (a plain SATA port won’t do), they run hotter and louder, and any used drive carries unknown prior hours. Buy from sellers who publish SMART data and offer returns, and read when used enterprise drives make sense before you commit.

2. Large CMR hard drives: the simple route

If you’d rather not touch SAS adapters or refurbished risk, big new conventional (CMR) internal drives are the no-drama path. Buy the capacity tier with the lowest $/TB — usually high-capacity but not the absolute newest flagship — and you reach 100 TB in a handful of drives. Insist on CMR rather than SMR for anything that lives in a NAS or array, because shingled drives can stall RAID rebuilds; our CMR vs SMR guide explains how to tell them apart.

3. Shucking external drives

Large external desktop drives are sometimes cheaper per terabyte than the bare internal drive inside them, because the finished product is priced for the mass market. ‘Shucking’ — removing the disk from its enclosure to use it bare — can shave real money off your $/TB. It voids the enclosure warranty and occasionally yields a drive with non-standard power pins, so it’s a tactic for the willing tinkerer, not a default.

4. Tape for the cold copy

You don’t need 100 TB of fast storage. Much of a big hoard is write-once, read-rarely, which is exactly what LTO tape is built for. On media cost per terabyte, tape beats every disk — and a written cartridge sits on a shelf for years drawing zero power. The drive is a real up-front investment and tape is sequential (poor at random access), so it only makes financial sense at scale or for the cold, off-site copy in a backup plan. For a 100 TB archive, that’s often a perfect fit.

RAID vs JBOD: how you arrange them matters

Reaching 100 TB usable is not the same as buying 100 TB of drives, because redundancy eats capacity:

• JBOD / single disks: every terabyte you buy is a terabyte you keep, but a single drive failure loses whatever was on it. Fine for replaceable data with backups elsewhere.
• RAID 5/6: single or double parity costs you one or two drives’ worth of capacity in exchange for surviving a failure (or two) without downtime. Budget the extra drives into your 100 TB target.
• RAID 10: fast and resilient, but you lose half your raw capacity — an expensive way to hit 100 TB.

Use the capacity calculator to see usable space after redundancy, and read RAID explained before deciding. One rule overrides all of it: RAID is not a backup — it survives a dead drive, not a deleted folder, ransomware or a fire.

The all-in cost beyond the drives

This is where the cheapest-drives plan can quietly become the most expensive build. Count the rest:

• Enclosure or NAS: a multi-bay NAS or a server chassis with enough bays, plus a SAS HBA if you went the enterprise route.
• Power and cooling: a wall of spinning drives draws real watts and needs airflow; over years, electricity is a line item, not a rounding error.
• Backups: 100 TB you can’t restore is 100 TB you can lose. A genuine plan needs a second copy — another set of disks or tape, ideally off-site, as in our 3-2-1 backup guide.
• Noise and space: enterprise drives are loud; plan where the machine lives.

The cheapest honest path is usually a hybrid: used enterprise or large CMR drives for the bulk pool, tape (or a second drive set) for the cold backup, sized with redundancy in mind. A few drives near the top of the value rankings are below — check the live $/TB rankings for today’s cheapest terabyte before buying in bulk.