Western Digital Red 2TB
NAS HDD
Part number WD20EFAX · Red series · SATA 6Gb/s (SATA III). If your machine is listed below, this drive is officially supported — not a forum workaround.
Part of the Western Digital Red series →
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Specifications are the manufacturer's published ratings for this product series; verify the exact part number before purchase.
Recording for this series is mixed CMR/SMR — it varies by exact model number. Verify the exact part number before buying a cold copy: SMR drives throttle writes once their internal cache is full, which is exactly what a full-library backup pass does — a 16 TB cold-copy backup that takes days will slow to crawl on the last terabytes. For the off-site slot of a 3-2-1 plan, prefer the CMR variant of the same capacity; the 3-2-1 guide and the backup tools encyclopedia cover the rest of the chain.
Compatibility verdict
It appears on the official compatibility lists of 195 machines and series — 147 QNAP, 48 TerraMaster. This is a NAS-class drive: built for 24/7 operation with vibration compensation for multi-bay enclosures — the right tier for most 1-8 bay home or small-office NAS units. Its series rating is on file as SMR (shingled) — the one trait that slows large RAID rebuilds and full-library copies.
Compatible NAS models
Same-capacity alternatives
Other drives listed at 2 TB capacity, ranked by how many machines list them:
Quick answers
Is the WD20EFAX officially compatible with my NAS?
It appears on the official compatibility lists of 195 machines and series — 147 QNAP, 48 TerraMaster. Every machine page linked below shows the vendor's own list entry, refreshed daily.
Is the WD20EFAX CMR or SMR?
As a Western Digital Red drive, it is rated CMR/SMR varies by model. CMR (conventional magnetic recording) is what a RAID array wants: SMR drives slow rebuilds dramatically. This series mixes both, so verify the exact part number before buying — the <a href="/faq/cmr-vs-smr-nas-drives/">CMR vs SMR guide</a> has a part-number lookup.
Is the WD20EFAX a good NAS drive?
This is a NAS-class drive: built for 24/7 operation with vibration compensation for multi-bay enclosures — the right tier for most 1-8 bay home or small-office NAS units. Its series rating is on file as SMR (shingled) — the one trait that slows large RAID rebuilds and full-library copies.
Can I use the WD20EFAX for a 3-2-1 cold backup copy?
Recording for this series is mixed CMR/SMR — it varies by exact model number. Verify the exact part number before buying a cold copy: SMR drives throttle writes once their internal cache is full, which is exactly what a full-library backup pass does — a 16 TB cold-copy backup that takes days will slow to crawl on the last terabytes. For the off-site slot of a 3-2-1 plan, prefer the CMR variant of the same capacity; the 3-2-1 guide and the backup tools encyclopedia cover the rest of the chain.
What are alternatives to the WD20EFAX?
At the same capacity, the most widely listed alternatives are Western Digital WD2005VBYZ (451 machines), Toshiba MG04ACA200E (416 machines), Seagate ST2000NE0015 (372 machines). The full ranked list is below.