Verdict

These are comparable SSDs. The WDS400T2R0A is rated for the most write endurance, so it lasts longest in a NAS that sees steady writes; for light use any is fine and price decides.

WDS400T1X0M
WD Black SN8100 · 4TB · Desktop
€736 (€184.00/TB)
WDS400T2R0A
WD Red SA500 · 4TB · NAS
€900 (€225.00/TB)

Value at a glance

Price / TB
WDS400T1X0M $175.00
WDS400T2R0A $212.50
Endurance (TBW)
WDS400T1X0M 2,400 TB
WDS400T2R0A 2,500 TB

Price history

DE · cheapest per day

WDS400T1X0M €736 WDS400T2R0A €900
zoomed · drag to zoom
€948 €613 €279 Sep 2024 Feb 2025 Jul 2025 Nov 2025 Apr 2026 Sep 2026
WDS400T1X0M WDS400T2R0A
Capacity 4 TB 4 TB
Form factor M.2 2.5
Interface NVMe SATA
NAND type TLC TLC
Endurance (TBW) 2,400 TB 2,500 TB
DWPD - -
DRAM cache Yes Yes
Power-loss protection No No
Sustained write - -
Cost / TBW $0.292 $0.340
Price / TB $175.00 $212.50
Buy
€736
View at Amazon →
€900
View at Amazon →

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.

WDS400T1X0M

No Backblaze failure data for this model.

WDS400T2R0A

No Backblaze failure data for this model.