Verdict

These are comparable SSDs. The SNV3510-800G 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.

SNV3510-400G
Synology SNV3510 · 0.4TB · NAS
No ES price yet
SNV3510-800G
Synology SNV3510 · 0.8TB · NAS
No ES price yet

Value at a glance

Endurance (TBW)
SNV3510-400G 491 TB
SNV3510-800G 1,022 TB
DWPD
SNV3510-400G 0.7
SNV3510-800G 0.7
SNV3510-400G SNV3510-800G
Capacity 0.4 TB 0.8 TB
Form factor M.2 M.2
Interface NVMe NVMe
NAND type TLC TLC
Endurance (TBW) 491 TB 1,022 TB
DWPD 0.7 0.7
DRAM cache - -
Power-loss protection Yes Yes
Sustained write - -
Cost / TBW - -
Price / TB - -
Buy No ES price yet No ES price yet

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.

SNV3510-400G

No Backblaze failure data for this model.

SNV3510-800G

No Backblaze failure data for this model.