Recording: WD2003FZEX lists CMR; WD20EZBX lists SMR.
Cache (MB): WD2003FZEX lists 64; WD20EZBX lists 256.
Manufacturer limited warranty: WD2003FZEX lists 5 years (eligible new drives); WD20EZBX lists 2 years (eligible new drives).
Sustained transfer (up to MB/s): WD2003FZEX lists 164; WD20EZBX lists 215.

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 WD2003FZEX and WD20EZBX
Specification	WD2003FZEX	WD20EZBX
Manufacturer	Western Digital	Western Digital
Product family	WD_BLACK	WD Blue
Model number	WD2003FZEX	WD20EZBX
Capacity (TB)	2	2
RPM	7200	7200
Interface	SATA 6Gb/s	SATA 6Gb/s
Recording	CMR	SMR
Cache (MB)	64	256
Form factor	3.5-inch	3.5-inch
Manufacturer limited warranty	5 years (eligible new drives)	2 years (eligible new drives)
Sustained transfer (up to MB/s)	164	215
Physical sector size (bytes)	Not recorded	4096

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

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