Interface: ST6000DM003 lists SATA 6 Gb/s; WD6003FZBX lists SATA 6Gb/s.
Recording: ST6000DM003 lists SMR; WD6003FZBX lists CMR.
Manufacturer limited warranty: ST6000DM003 lists 2 years (eligible new drives); WD6003FZBX lists 5 years (eligible new drives).

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 ST6000DM003 and WD6003FZBX
Specification	ST6000DM003	WD6003FZBX
Manufacturer	Seagate	Western Digital
Product family	BarraCuda	WD_BLACK
Model number	ST6000DM003	WD6003FZBX
Capacity (TB)	6	6
Interface	SATA 6 Gb/s	SATA 6Gb/s
Recording	SMR	CMR
Cache (MB)	256	256
Form factor	3.5-inch	3.5-inch
Load/unload cycles	600000	Not recorded
Power-on hours per year	2400	Not recorded
Workload rating (TB/year)	55	Not recorded
Manufacturer limited warranty	2 years (eligible new drives)	5 years (eligible new drives)
RPM	Not recorded	7200
Sustained transfer (up to MB/s)	Not recorded	227

Compatibility and buying checks

One or both drives use SMR recording. Check sustained-write and array requirements before choosing one for a NAS or a write-heavy workload.
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.