Seagate IronWolf Pro HDD 20TB vs Western Digital WD Red Pro HDD 20TB

SeagateIronWolf Pro HDD 20TB20000 GB · 7200 · 256 MB · 3.5-inch
Western DigitalWD Red Pro HDD 20TB20000 GB · 7200 · 256 MB · 3.5-inch
In short

The site holds no current price for at least one of these, so what follows compares specifications alone.

SpecificationSeagateIronWolf Pro HDD 20TBWestern DigitalWD Red Pro HDD 20TB
Capacity (GB)2000020000
Current best price
Price per TB
RPM72007200
Cache (MB)256256
Form factor3.5-inch3.5-inch
Warranty (years)55

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.

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

With a price missing for at least one side, there is no cost verdict to give. What separates two otherwise-similar drives is up in the sections above — how fast the platters spin, how much cache each carries, the form factor and the warranty — so weigh those against what your build needs.

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.
Should you buy Seagate IronWolf Pro HDD 20TB or Western Digital WD Red Pro HDD 20TB?
With a price missing for at least one side, there is no cost verdict to give. What separates two otherwise-similar drives is up in the sections above — how fast the platters spin, how much cache each carries, the form factor and the warranty — so weigh those against what your build needs.
How we track prices

Related comparisons