Verdict

For a NAS cache or write-heavy pool, the WDS400T2R0A is the safer pick - the WDS400T4B0E uses QLC NAND, which wears out faster and slows badly under sustained writes (light, read-mostly use only).

WDS400T2R0A
WD Red SA500 · 4TB · NAS
€900 (€225.00/TB)
WDS400T4B0E
WD Blue SN5000 · 4TB · Desktop
€464 (€116.00/TB)

Value at a glance

Price / TB
WDS400T2R0A $212.50
WDS400T4B0E $121.36
Endurance (TBW)
WDS400T2R0A 2,500 TB
WDS400T4B0E 1,200 TB

Price history

DE · cheapest per day

WDS400T2R0A €900 WDS400T4B0E €464
zoomed · drag to zoom
€948 €613 €279 Sep 2024 Feb 2025 Jul 2025 Nov 2025 Apr 2026 Sep 2026
WDS400T2R0A WDS400T4B0E
Capacity 4 TB 4 TB
Form factor 2.5 M.2
Interface SATA NVMe
NAND type TLC QLC
Endurance (TBW) 2,500 TB 1,200 TB
DWPD - -
DRAM cache Yes No
Power-loss protection No No
Sustained write - -
Cost / TBW $0.340 $0.405
Price / TB $212.50 $121.36
Buy
€900
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€464
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Highlighted cells mark the stronger spec for a NAS build. Failure rates from Backblaze Drive Stats where available; $/TB uses the cheapest live price. Buy links are Amazon affiliate.

WDS400T2R0A

No Backblaze failure data for this model.

WDS400T4B0E

No Backblaze failure data for this model.