Interface: ST12000NE0008 lists SATA 6 Gb/s; WD121KFBX lists SATA 6Gb/s.
Sustained transfer (up to MB/s): ST12000NE0008 lists 250; WD121KFBX lists 240.

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 ST12000NE0008 and WD121KFBX
Specification	ST12000NE0008	WD121KFBX
Manufacturer	Seagate	Western Digital
Product family	IronWolf Pro	WD Red Pro
Model number	ST12000NE0008	WD121KFBX
Capacity (TB)	12	12
RPM	7200	7200
Interface	SATA 6 Gb/s	SATA 6Gb/s
Cache (MB)	256	256
Form factor	3.5-inch	3.5-inch
Power-on hours per year	8760	Not recorded
Average operating power (W)	7.8	Not recorded
Rotational vibration sensors	Yes	Not recorded
Manufacturer limited warranty	5 years (eligible new drives)	5 years (eligible new drives)
Sustained transfer (up to MB/s)	250	240
Recording	Not recorded	CMR
Workload rating (TB/year)	Not recorded	550
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.