Verdict

For a NAS cache or write-heavy pool, the WDS400T2R0A is the safer pick - the MZ-77Q4T0 uses QLC NAND, which wears out faster and slows badly under sustained writes (light, read-mostly use only).

MZ-77Q4T0
Samsung 870 QVO · 4TB · Desktop
No ES price yet
WDS400T2R0A
WD Red SA500 · 4TB · NAS
€860 (€215.00/TB)

Value at a glance

Price / TB
MZ-77Q4T0 $223.56
WDS400T2R0A $200.00
Endurance (TBW)
MZ-77Q4T0 1,440 TB
WDS400T2R0A 2,500 TB

Price history

ES · cheapest per day

WDS400T2R0A €860
zoomed · drag to zoom
€1,064 €685 €306 Aug 2024 Jan 2025 Jun 2025 Nov 2025 Mar 2026 Aug 2026
MZ-77Q4T0 WDS400T2R0A
Capacity 4 TB 4 TB
Form factor 2.5 2.5
Interface SATA SATA
NAND type QLC TLC
Endurance (TBW) 1,440 TB 2,500 TB
DWPD - -
DRAM cache Yes Yes
Power-loss protection No No
Sustained write 160 MB/s -
Cost / TBW $0.621 $0.320
Price / TB $223.56 $200.00
Buy No ES price yet
€860
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.

MZ-77Q4T0

No Backblaze failure data for this model.

WDS400T2R0A

No Backblaze failure data for this model.