RPM: ST4000NT001 lists 7200; WD40EFZZ lists 5400.
Interface: ST4000NT001 lists SATA 6 Gb/s; WD40EFZZ lists SATA 6Gb/s.
Cache (MB): ST4000NT001 lists 256; WD40EFZZ lists 128.
Workload rating (TB/year): ST4000NT001 lists 550; WD40EFZZ lists 180.
Manufacturer limited warranty: ST4000NT001 lists 5 years (eligible new drives); WD40EFZZ lists 3 years (eligible new drives).
Sustained transfer (up to MB/s): ST4000NT001 lists 250; WD40EFZZ lists 180.

A larger cache, higher RPM or higher advertised sequential speed alone does not establish which drive is better for your workload.

Specifications side by side

Show differences only

Manufacturer specifications for ST4000NT001 and WD40EFZZ
Specification	ST4000NT001	WD40EFZZ
Manufacturer	Seagate	Western Digital
Product family	IronWolf Pro	WD Red Plus
Model number	ST4000NT001	WD40EFZZ
Capacity (TB)	4	4
RPM	7200	5400
Interface	SATA 6 Gb/s	SATA 6Gb/s
Recording	CMR	CMR
Cache (MB)	256	128
Form factor	3.5-inch	3.5-inch
Power-on hours per year	8760	Not recorded
Workload rating (TB/year)	550	180
Average operating power (W)	8.7	Not recorded
Rotational vibration sensors	Yes	Not recorded
Manufacturer limited warranty	5 years (eligible new drives)	3 years (eligible new drives)
Sustained transfer (up to MB/s)	250	180
NAS bays	Not recorded	8
Physical sector size (bytes)	Not recorded	4096

Compatibility and buying checks

Compare new and renewed offers separately. The manufacturer specification does not guarantee the warranty or return policy of a marketplace seller.

Reviewed 2026-09-07. Published specifications; no independent benchmark or failure-rate claim.

Reviewed 2026-08-21. Published specifications; no independent benchmark or failure-rate claim.