Verdict

For a NAS cache or write-heavy pool, the LNM790X004T-RNNNU is the safer pick - the WDS400T4B0E uses QLC NAND, which wears out faster and slows badly under sustained writes (light, read-mostly use only).

LNM790X004T-RNNNU
Lexar NM790 · 4TB · Desktop
£715 (£178.65/TB)
WDS400T4B0E
WD Blue SN5000 · 4TB · Desktop
£400 (£100.00/TB)

Value at a glance

Price / TB
LNM790X004T-RNNNU $178.25
WDS400T4B0E $120.00
Endurance (TBW)
LNM790X004T-RNNNU 3,000 TB
WDS400T4B0E 1,200 TB

Price history

UK · cheapest per day

LNM790X004T-RNNNU £715 WDS400T4B0E £400
zoomed · drag to zoom
£717 £543 £370 Aug 21 Sep 2 Sep 14 Sep 26 Oct 8 Oct 21
LNM790X004T-RNNNU WDS400T4B0E
Capacity 4 TB 4 TB
Form factor M.2 M.2
Interface NVMe NVMe
NAND type TLC QLC
Endurance (TBW) 3,000 TB 1,200 TB
DWPD - -
DRAM cache No No
Power-loss protection No No
Sustained write - -
Cost / TBW $0.238 $0.400
Price / TB $178.25 $120.00
Buy
£715
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£400
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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.

LNM790X004T-RNNNU

No Backblaze failure data for this model.

WDS400T4B0E

No Backblaze failure data for this model.