Seagate IronWolf Pro HDD 20TB vs Western Digital WD Red Pro HDD 20TB
On the measures that settle this, Seagate IronWolf Pro HDD 20TB never comes out behind, and on at least one it comes out ahead.
| Specification | SeagateIronWolf Pro HDD 20TB | Western DigitalWD Red Pro HDD 20TB |
|---|---|---|
| Capacity (GB) | 20000 | 20000 |
| Current best price | $994.99betterat Amazon.ca · captured 2026-09-13 | $1,199.99at Amazon.ca · captured 2026-09-12 |
| Price per TB | $49.75better | $60.00 |
| RPM | 7200 | 7200 |
| Cache (MB) | 256 | 256 |
| Form factor | 3.5-inch | 3.5-inch |
| Warranty (years) | 5 | 5 |
How these two compare
Sequential throughput
Seagate IronWolf Pro HDD 20TB holds the higher sequential rate. Seagate IronWolf Pro HDD 20TB is rated 285 MB/s read and 285 MB/s write, Western Digital WD Red Pro HDD 20TB 267 MB/s read and 267 MB/s write; a spinning disk's throughput rises with platter speed and density and barely differs between reading and writing.
Price
Seagate IronWolf Pro HDD 20TB lists at $994.99, or $49.75 per TB; Western Digital WD Red Pro HDD 20TB at $1,199.99, or $60.00 per TB.
Spindle speed
Both turn at 7200 RPM. Spindle speed sets how quickly the head reaches data and how much power and noise the drive makes, and at an identical RPM the two land in the same place on all of it.
Cache
Seagate IronWolf Pro HDD 20TB carries 256 MB of onboard cache and Western Digital WD Red Pro HDD 20TB carries 256 MB — the buffer the drive uses to absorb bursts of writes and hold recently read data, smoothing over the mechanical delay of moving the head. More cache helps most under bursty, mixed workloads; for one long sequential transfer it barely matters.
Warranty
Seagate IronWolf Pro HDD 20TB carries a 5-year warranty and Western Digital WD Red Pro HDD 20TB a 5-year one — how long the maker will replace a failed drive, and a rough read on the confidence it has in the mechanism.
Which to buy
Seagate IronWolf Pro HDD 20TB. It gives up nothing to the other on the measures the site tracks and leads on at least one, so there is no trade to weigh — the sections above show where the margin is.
Common questions about this pair
- Which is faster, Seagate IronWolf Pro HDD 20TB or Western Digital WD Red Pro HDD 20TB?
- Seagate IronWolf Pro HDD 20TB holds the higher sequential rate. Seagate IronWolf Pro HDD 20TB is rated 285 MB/s read and 285 MB/s write, Western Digital WD Red Pro HDD 20TB 267 MB/s read and 267 MB/s write; a spinning disk's throughput rises with platter speed and density and barely differs between reading and writing.
- Which costs less per terabyte, Seagate IronWolf Pro HDD 20TB or Western Digital WD Red Pro HDD 20TB?
- Seagate IronWolf Pro HDD 20TB lists at $994.99, or $49.75 per TB; Western Digital WD Red Pro HDD 20TB at $1,199.99, or $60.00 per TB.
- Should you buy Seagate IronWolf Pro HDD 20TB or Western Digital WD Red Pro HDD 20TB?
- Seagate IronWolf Pro HDD 20TB. It gives up nothing to the other on the measures the site tracks and leads on at least one, so there is no trade to weigh — the sections above show where the margin is.