Technical reference
Western Digital WD Red Pro WD4005FFBX 4TB specifications
One retail 4TB 3.5-inch SATA WD4005FFBX. Enclosure, extra drives and RAID are separate.
Complete specifications with requirements, upgrade limits and sources. For our buying judgment, reviews and prices, return to the buying guide.
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Search all 42 specifications, including conditions and limits.
Identity
Exact 4TB air CMR SKU.
| Exact model | WD4005FFBX[1] |
|---|---|
| Marketed capacity | 4 TB[1] Decimal capacity; formatting, filesystem and redundancy reduce usable space. |
| Form factor | 3.5-inch[1] |
| Interface | SATA 6 Gb/s[1] |
| Recording technology | CMR[1] |
| Drive atmosphere | Air[1] |
| Advanced Format | Yes[1] The table confirms AF; it does not separately specify the logical sector size. |
| Native command queuing | Yes[1] |
| RoHS compliant | Yes[1] EU 2011/65/EU and 2015/863. |
| Factory / retail suffix observed | WD4005FFBX-68CAUN0 (Nero Score model string); B&H URL uses WD4005FFBX-SPCAUN0[1][8] Suffixes are packaging/factory codes on the same MPN, not a different capacity. |
Performance
7200 rpm and 267 MB/s data-sheet rating.
| Spindle speed | 7200 RPM[1] |
|---|---|
| Cache | 256 MB[1] |
| Maximum internal transfer rate | 267 MB/s[1][2] Unresolved official conflict on 2026-09-11: the January 2025 data-sheet column lists 267 MB/s (footnote 3, up to, read-based) while the US store specification block prints a lower figure that is numerically the same as the adjacent previous-generation column. That numerical match is suggestive, not proof of a page-implementation error. Do not average or silently pick one. |
NAS and reliability
550 TB/year, 2M-hour MTBF, 5-year warranty, no OptiNAND.
| NAS bay rating | Unlimited[1][2] Rating does not establish exact enclosure/firmware compatibility. Family highlight and store Compatibility line: RAID-optimized NAS systems with unlimited # of bays. Not a per-column table cell. Does not replace a vendor HCL check. |
|---|---|
| Operation | 24 × 7[1] |
| NASware | NAS-optimized drive parameters[1] |
| Dual-plane balance control | Yes[1] |
| Annual workload rate | 550 TB/year[1] Footnote 6: annualized TB transferred × (8760 / power-on hours); maximum rating specified at typical 40 °C. Not a lifetime TBW guarantee. |
| MTBF rating | 2 million hours[1][2] Footnote 5: projected sample MTBF at 220 TB/year and 40 °C; derates above those parameters up to 550 TB/year. Does not predict one drive and is not a warranty. This air column is 2,000,000 hours, not the helium 2.5M-hour family headline. |
| Load/unload cycles | 600, 000[1] Controlled unload at ambient conditions. |
| Nonrecoverable read errors | <1 in 10^15 bits read[1] |
| Limited warranty | 5 years[1] Region-specific conditions apply; confirm seller and serial number coverage. |
| Rotational vibration sensors | Yes[1] |
| OptiNAND | No[1][2] Data sheet column is No. The US store specification block lists Technologies NASware, OptiNAND, ArmorCache for this SKU; that is family template copy, not this column. |
| Multi-axis shock sensor | Yes[1] |
| Time-Limited Error Recovery (TLER) | Claimed on the US store RAID copy for the Red Pro family[2] Not a labeled cell in the January 2025 specification table. Confirm in your NAS firmware if TLER/ERC matters. |
Power and acoustics
5.8/4.0/0.3 W; 29/36 dBA.
| Peak 12V current | 2 A[1] 12VDC ±10%; allow for simultaneous drive startup. |
|---|---|
| Average read/write power | 5.8 W[1][2] Footnote 8: power measurements at room-ambient temperature. Not NAS-pack watts. 4TB column 5.8 W vs 6.9 W on 6/8TB air columns. |
| Average idle power | 4 W[1] Room/ambient-temperature measurement. |
| Standby / sleep power | 0.3 W[1] Room/ambient-temperature measurement. |
| Idle acoustics | 29 dBA[1] Manufacturer rating; not room noise at your listening position. |
| Average seek acoustics | 36 dBA[1] Enclosure vibration and placement affect perceived noise. |
Environment and dimensions
0–65 °C operating; 720 g class.
| Operating temperature | 0 °C to 65 °C[1] |
|---|---|
| Non-operating temperature | −40 °C to 70 °C[1] |
| Operating shock, read/write | 70 g, 2 ms[1] |
| Operating shock, read | 70 g, 2 ms[1] |
| Non-operating shock | 300 g, 2 ms[1] |
| Maximum height / length | 26.1 /147 mm[1] |
| Width | 101.6 mm ±0.254 mm[1] |
| Weight | 720 g ±3%[1][2] Data sheet 1.58 lb / 0.72 kg ±3%. US store specification block lists 715gms for this SKU. |
| Country of origin, table | Thailand[1] Check the supplied drive label; manufacturing origin may change. |
Compliance
Store certification list.
| Store-listed certifications | BSMI, ICES-003/NMB-003, CE, FCC, KC, Maghreb, RCM, UKCA, VCCI, CB-Scheme, TUV, UL[2] Copied from the 2026-09-11 US store specification block for this SKU. |
|---|
Exact product identity & open questions
- Capacity / quantity
- 4 TB / one drive[1]
- Revision rule
- Do not treat WD4003FFBX, WD4002FFWX, WD4001FFSX or unlabeled “Red Pro 4TB” as this SKU.[1]
- Exact-model independent tests: No professional original lab test with method, charts and the exact current MPN was adopted. Older Red Pro capacities (WD4001FFSX, WD4003FFBX, WD6003FFBX, WD8003FFBX) are related family history only. User-submitted Nero Score and one Kakaku install note do not replace a controlled NAS benchmark.
- Exact NAS compatibility: WD store copy says RAID-optimized NAS with unlimited bay count and mentions vendor testing, but Synology and QNAP public HCL pages did not return a usable exact-MPN qualification table in this round (JS/search shells). Confirm the enclosure, DSM/QTS version and the exact MPN on the vendor list before buying an array.
- Family comparison video unread: YouTube DXM7znUSIPg (SomeTechGuy, WD Red Plus/Pro vs IronWolf/Pro) was found by title only. No ASR or identity frames were obtained. Do not treat it as a measured result for these MPNs.
- Official transfer-rate conflict: Unresolved official conflict: data sheet 267 MB/s vs US store 217 MB/s for WD4005FFBX on 2026-09-11. Equality with the WD4003FFBX cell is suggestive, not proof of a wrong column.
- Current US offer coverage: Newegg primary pane 2026-09-11: Sold by Newegg, $244.99, IsNew, in stock, ShippingCharge 0.01; H1 vs Model identity conflict preserved. Amazon PDP pending (no selected new buy box). B&H/MemoryC blocked. WD store has no numeric price.
Sources
Research updated Sep 11, 2026. Individual source check dates are listed below. Measurements belong to the named reviewers; tested configurations and software versions may differ from the product you buy.
- [1] Western Digital WD Red Pro datasheet (January 2025) ↗
Checked Sep 11, 2026 · Page 4 WD4005FFBX column plus footnotes 1–8 and page 1 unlimited-bays highlight
- [2] WD US store: 4TB WD Red Pro WD4005FFBX ↗
Checked Sep 11, 2026 · Selected 4TB variant; Specifications block; Key Features; Disclosures 1–4
- [3] Newegg WD4005FFBX product listing ↗
Checked Sep 11, 2026 · H1/pn WD4005FFBX; Sold by Newegg; $244.99; Instock true
- [4] B&H WD4005FFBX product listing ↗
Checked Sep 11, 2026 · Historical 2026-09-08 observation; 2026-09-11 Cloudflare challenge
- [5] Western Digital WD4005FFBX product listing ↗
Checked Sep 11, 2026 · Manufacturer PDP; price/inventory remain unresolved templates
- [6] Amazon WD4005FFBX detail page B0D1V6F7Y9 ↗
Checked Sep 11, 2026 · Title WD4005FFBX; unqualifiedBuyBox; no selected new main offer
- [7] Kakaku.com user review 1906010 of WD4005FFBX ↗
Checked Sep 11, 2026 · Review 2024-11-24; RAID6 HP NAS hot-swap narrative
- [8] Nero Score user results for WDC WD4005FFBX-68CAUN0 ↗
Checked Sep 11, 2026 · User-submitted sequential 254/253 MB/s; first-seen date 08/2021 is inconsistent with this SKU
- [9] iXBT forum report of a relabeled WD4005FFBX from Citilink ↗
Checked Sep 11, 2026 · Single-user claim: Hitachi relabel, edited firmware, speed far below rating; Russian retailer, not a US offer
- [10] Western Digital warranty policy ↗
Checked Sep 11, 2026 · Region-specific limited warranty details linked from data sheet footnote 7 / store disclosure 4
Research and review record
- Research: Grok 4.6 · Source research and data update
- Self-check: Grok 4.6 · Researcher self-check
- Independent review: GPT-6 (Codex) · Exact Jan2025 WD Red Pro4/6/8TB columns and footnotes, conflicting official store values, exact current merchant primary offers and dated historical rows; bounded Kakaku user experience for4TB. No exact-MPN lab benchmark claimed; gaps and index decisions preserved.
- Editorial integration: GPT-6 (Codex) · Editorial integration and validation
Independent review completed for the scope recorded in the audit.
Source evidence and review history (JSON)