The cheapest 3TB hard drive in stock right now is the HGST HUS724030ALS640 3TB SAS 6G at $15.13/TB ($45.39 total, Refurb). 21 of 25 tracked 3TB drives are in stock, with new starting at $23.00/TB and refurbished at $15.13/TB.
A value tier dominated by enterprise SAS pulls, which is why the cheapest $/TB on the whole site is often found here rather than at a modern capacity. The catch is the interface: most 3TB stock is SAS, needing a host bus adapter. 3TB SATA exists but is priced well above the SAS equivalent.
Some 3TB consumer drives use Shingled Magnetic Recording (SMR) which causes catastrophic RAID rebuild failures. WD Red (non-Plus) and certain Seagate Barracuda models at this capacity are SMR — avoid them for any RAID deployment. All enterprise 3TB SATA drives (Seagate Exos, WD Ultrastar) and the WD Red Plus consumer NAS line are CMR. Verify recording technology before purchase.
One 3TB hard drive, in decimal units (1TB = 1,000GB), before file-system and RAID overhead. Each line is a division you can redo; the per-file sizes are our assumptions and say so.
Security cameras, recording continuously: 86 camera-days - 8 cameras for 10 days. The arithmetic: 3.2 Mbps ÷ 8 = 0.4 MB/s × 86,400 s = 34.56 GB per camera-day; 3,000 GB ÷ 34.56 = 86 camera-days. The bitrate is WD's reference figure for one stream (single stream, 1080p, h.265, 25fps), from WD Purple / WD Purple Pro data sheets (footnote 3); the 8-camera count is our example. A camera set to a higher bitrate fills the drive proportionally faster.
Guides for this capacity: the HDD price forecast · fill a NAS at today's prices
Every listing we track at this size - 17 product pages, including ones with no current offer. Out-of-stock pages carry specs and in-stock alternatives, never a stale price.
At the 3TB capacity tier, the refurbished market typically prices 20-30% below new drive equivalents. Right now, the cheapest new 3TB drive is Seagate ST3000NM0023 3TB SAS 6G 7.2K at $23.00/TB and the cheapest refurbished is HGST HUS724030ALS640 3TB SAS 6G at $15.13/TB — a 34% discount for refurb. For backup repositories, RAID 6 capacity tiers, and any deployment with redundancy, refurbished is the right answer. For primary production storage and single-drive deployments, the new drive premium buys peace of mind through full manufacturer warranty and zero accumulated wear.
Established refurbished resellers like MDD MaxDigitalData source from decommissioned hyperscale datacenters and provide 3-5 year reseller warranties at this capacity. Run smartctl on arrival, deploy in RAID 6 with at least one hot spare, and monitor SMART attributes continuously.
Bulk cold storage and archive tiers where the SAS interface is already present. In a server with spare bays and an existing HBA, 3TB SAS pulls are frequently the cheapest usable terabyte available anywhere on this site.
RAID guidance: RAID 5 acceptable, RAID 6 preferred in larger SAS shelves where drive count makes a second failure during rebuild plausible. Use the RAID Capacity Planner to calculate exact usable capacity for any configuration at this capacity.
Power draw: 3TB enterprise SATA drives typically draw 6-9W active, 4-5W idle. Six 3TB drives in a NAS array consume approximately 35-55W active — modest by enterprise standards but meaningful for home electricity costs over years of operation.
When to size up: If your projected capacity growth over the next 24 months would exceed the array's usable capacity at 3TB drives, sizing up one tier (7TB or larger) defers the next expansion cycle and typically improves $/TB. Sizing down rarely makes financial sense unless bay count is the binding constraint.
3TB is where the secondary market produces its most striking prices. Retired enterprise SAS drives at this capacity regularly land at the lowest cost per terabyte anywhere in our catalogue, below drives ten times their size, because the supply is large and the demand is small. The constraint is entirely the interface. SAS needs a host bus adapter — an LSI/Broadcom 9211-8i or similar in IT mode is the standard answer — plus the right cabling, and none of that is worth buying for a single drive. If the controller is already in the machine, 3TB SAS pulls are close to free storage. If it is not, the 3TB SATA listings are priced well above the SAS ones and the economics disappear. Check the interface column before you buy on price alone.
Usable capacity examples for 3TB drives at common deployment sizes, using RAID 5 (single parity, one drive of overhead) and RAID 6 (dual parity, two drives of overhead):
| Drives | Raw | RAID 5 usable | RAID 6 usable |
|---|---|---|---|
| 4 drives | 12TB | 9TB | 6TB |
| 6 drives | 18TB | 15TB | 12TB |
| 8 drives | 24TB | 21TB | 18TB |
| 10 drives | 30TB | 27TB | 24TB |
| 12 drives | 36TB | 33TB | 30TB |
At 3TB per drive, RAID 5 remains acceptable for non-critical deployments because rebuild windows are short and URE risk is manageable. For production storage, RAID 6 still provides better protection at modest capacity cost.
Rebuild time for a 3TB drive in a RAID 6 array typically runs 9-15 hours at typical hardware-accelerated rebuild speeds (assuming the array is not heavily loaded with production traffic during rebuild). Throughout the rebuild window, the array operates at degraded performance and reduced redundancy. Hot spare drives that automatically begin rebuild on first failure shrink the exposure window to minutes rather than hours. Use the RAID Capacity Planner to model rebuild times for your specific drive count and array configuration.
Enterprise 3TB SATA hard drives typically draw 6-10W during active read/write and 4-5W at idle. For a 6-drive array running 24/7 with mixed activity, expect approximately 35-55W of continuous power draw plus the host system's overhead. At typical US residential electricity rates of $0.16/kWh, a 45W array costs about $63 per year in electricity; at commercial rates of $0.10/kWh, about $39 per year.
Fewer high-capacity drives dramatically reduce power consumption per terabyte stored. Six 3TB drives delivering 12TB usable in RAID 6 consume the same power as six 4TB drives delivering only 16TB usable — but at 100% of the capacity per watt. For datacenter and homelab deployments where electricity is a meaningful operating cost, sizing up to 3TB drives delivers better power efficiency per TB stored alongside the $/TB advantage. The TCO Calculator models the full 5-year power cost for any drive configuration.
Enterprise hard drive prices have risen approximately 46-50% since September 2025, driven by AI infrastructure demand absorbing hyperscale HDD production, US import tariffs adding 10-13% to landed costs, and NAND shortages forcing buyers from SSD to HDD for capacity tiers. Smaller capacity tiers including 3TB have seen more modest 15-30% increases as they are less directly consumed by hyperscale AI workloads. Refurbished supply at this capacity remains ample from older hyperscale decommissions. Read the full analysis in Hard Drive Prices Up 50% in 2026.
Most storage analysts expect elevated pricing to persist through 2026 and into 2027. New NAND capacity takes 2-3 years to qualify and ramp; hyperscale AI buildouts are not expected to moderate before late 2026. For 3TB buyers in particular, the practical procurement advice is to purchase current requirements at today's prices rather than deferring in anticipation of price normalization. Monitor live $/TB on this page and on the cheapest per TB tracker for the current best deal at this capacity.
As of the most recent refresh, the cheapest 3TB hard drive on DatacenterDisk is the HGST HUS724030ALS640 3TB SAS 6G at $15.13/TB ($45.39 total). Prices update about once a day; check the live table above for the current winner.
3TB is appropriate for single-drive external backups, small business document storage, or as a starting point for first-time NAS buyers. For Plex or production NAS, sizes above 16TB deliver meaningfully better $/TB and longer service life.
Some 3TB consumer drives use SMR (Shingled Magnetic Recording) which is unsuitable for RAID arrays — RAID rebuilds can take days and may fail entirely. All enterprise 3TB SATA drives (Seagate Exos, WD Ultrastar) use CMR. Verify the specific model on the manufacturer's spec sheet before purchasing if you plan to use RAID.
Cheapest new 3TB right now: Seagate ST3000NM0023 3TB SAS 6G 7.2K at $23.00/TB with full manufacturer warranty. Cheapest refurbished: HGST HUS724030ALS640 3TB SAS 6G at $15.13/TB with reseller warranty. Refurbished is appropriate for RAID 6 backup and capacity tiers; new for primary production storage.
Live market shows 3TB drives starting at $15.13/TB ($45.39 total for the cheapest in-stock listing). For new enterprise CMR drives at this capacity, expect $20-23/TB depending on brand and series. The DatacenterDisk live tracker has the most current pricing.
At 3TB capacity, NAS-specific lines are limited. Look for CMR drives only — verify recording technology on the manufacturer spec sheet before purchasing. Seagate IronWolf, WD Red Plus (NOT WD Red), and Toshiba N300 are the safe NAS-branded options.