32TB enterprise SMR buying authority

WD Ultrastar DC HC690 32TB UltraSMR

Verified spec guide ·

The WD Ultrastar DC HC690 32TB is WD's highest-density Ultrastar model in this batch, but it is not a universal 32TB enterprise disk. It is an UltraSMR product for environments that can manage shingled/zoned write behavior.

For hyperscale and bulk-storage teams, that density can change rack economics. For normal NAS, workstation and unqualified RAID environments, the same recording architecture can be the reason not to buy it.

Model
WSH723220ALN6L4
Capacity
32TB
Recording
UltraSMR / host-managed SMR
Interface
SATA 6Gb/s and SAS 12Gb/s variants
Quick answer

Choose HC690 32TB when your storage stack is already qualified for UltraSMR/host-managed SMR and rack density is the binding constraint. Choose a CMR 32TB drive, such as Seagate Exos or IronWolf Pro, when the host expects conventional random-write block behavior.

Best fit

Ultrastar HC690 32TB specifications

Manufacturer-published values for the exact product family. Retail listings can collapse these details, so match the part number before ordering.

SpecModel number
ValueWSH723220AL4201, WSH723220AL4204, WSH723220ALN601, WSH723220ALN604, WSH723220ALN6L1, WSH723220ALN6L4
SpecCapacity
Value32TB decimal marketed capacity
SpecRecording technology
ValueUltraSMR / host-managed SMR
SpecPlatform
Value11-disk OptiNAND and UltraSMR generation
SpecInterface
ValueSATA 6Gb/s and SAS 12Gb/s variants
SpecSector format
Value512e/4Kn family variants; interface and format code must match host support
SpecSpindle speed
Value7200 RPM
SpecCache / buffer
Value512MB
SpecMaximum sustained transfer rate
Value269MB/s maximum sustained transfer rate on 32TB SATA/SAS variants
SpecWorkload rating
Value550TB/year
SpecReliability rating
Value2.5M hours projected
SpecWarranty
Value5-year limited warranty
SpecPower
Value5.5W idle SATA / 5.8W idle SAS; 9.4W SATA / 9.7W SAS random read 4KB QD=8 at max IOPS
SpecAcoustics
Value2.5/3.2 Bels idle/operating typical
SpecOperating temperature
Value5C to 60C operating; -40C to 70C non-operating
SpecCompatibility note
ValueHyperscale and bulk-storage fit where the host stack manages SMR zones deliberately.
Current market status

No exact in-stock live row is currently matched for WSH723220AL4201, WSH723220AL4204, WSH723220ALN601, WSH723220ALN604, WSH723220ALN6L1, WSH723220ALN6L4. Relevant live alternatives are shown so the page does not collapse into an empty catalogue.

Relevant live alternatives ranked by current $/TB

Live prices · updated every 4-5 hours · last checked 2 min ago · exact model not currently matched in live stock

Best $/TB in this tier
3TB HUS724030ALS640 CMR at $15.13/TB — $45 for 3TB
3TB HUS724030ALS640
CMR
3TB · 7200rpm · TB/yr · yr
$15.13/TB · $45Buy
4TB HUS726040ALS210
CMR
4TB · 7200rpm · TB/yr · yr
$16.15/TB · $65Buy
3TB HUS724030ALA640
CMR
3TB · 7200rpm · TB/yr · yr
$20.00/TB · $60Buy
10TB HUH721010AL5200
CMR
10TB · 7200rpm · TB/yr · 5yr
$23.50/TB · $235Buy
14TB WUH721414ALE604
CMR
14TB · 7200rpm · TB/yr · yr
$24.29/TB · $340Buy
4TB HMS5C4040ALE640
CMR
4TB · 7200rpm · TB/yr · yr
$24.75/TB · $99Buy
14TB WUH721414ALE6L4
CMR
14TB · 7200rpm · TB/yr · yr
$25.00/TB · $350Buy
14TB WUH721414ALE604
CMR
14TB · 7200rpm · TB/yr · yr
$25.00/TB · $350Buy

Workload rating is recorded per part number from Seagate's datasheet for that exact model, not blanketed across the line — two drives of the same capacity can differ because they are different generations. A dash means the figure is not stated for that listing. Recording technology comes from the manufacturer's published CMR/SMR list; a model absent from that list is shown as UNVERIFIED rather than guessed. Rows priced above 3× this line's in-stock median are flagged and excluded from the winner callout and from every median we compute.

Live acquisition math for exact matches

This table is computed from live DatacenterDisk rows when an exact in-stock match exists. It is intentionally blank for unavailable models rather than filled with stale prices.

No exact in-stock row is available right now. Use the availability table for nearby live alternatives, then re-check the exact model before ordering.

32TB deployment math

Raw capacity is not usable capacity. This table shows the slot-level math before filesystem overhead, snapshots, reserved space and vendor-specific parity layouts.

Drive count4 bays
Raw capacity128TB
Single-parity usable96TB
Dual-parity usable64TB
Drive count6 bays
Raw capacity192TB
Single-parity usable160TB
Dual-parity usable128TB
Drive count8 bays
Raw capacity256TB
Single-parity usable224TB
Dual-parity usable192TB
Drive count12 bays
Raw capacity384TB
Single-parity usable352TB
Dual-parity usable320TB

Density is the point

HC690 32TB is about terabytes per slot, per shelf and per rack. In 60 bays it delivers 1.92PB raw before parity and overhead. That can reduce the number of shelves, cables, HBAs and rack units needed for a retention tier.

Those gains matter most where the workload is already aligned: large sequential ingest, append-heavy repositories, object storage and storage software that can direct writes around SMR constraints.

Compatibility is the gate

A host-managed SMR environment is not just a drive purchase. The OS, filesystem, block layer, controller path and application must all preserve the rules the media requires. If any layer hides or violates those rules, the drive can be a poor fit even if it enumerates on the bus.

This is the reason CMR drives still exist at 26TB, 30TB and 32TB. They are less dense in some families, but they match the behavior conventional storage stacks expect.

Power and cooling economics

The HC690 sheet lists low idle watts per TB, which is where density helps. Fewer drives and shelves can reduce platform overhead. The drive itself still dissipates heat, and a dense rack full of 32TB disks needs airflow designed for continuous enterprise operation.

Do not evaluate HC690 only by per-drive watts. Model enclosure fans, controller cards, shelves and rebuild windows. The most useful number is cost and watts per protected terabyte delivered by the whole system.

Final verdict

HC690 32TB is a strong hyperscale and enterprise-retention part when the architecture is ready for it. It is weak as a retail substitute for a CMR 32TB drive because the incompatibility risk overwhelms the capacity gain.

If you cannot name the SMR-aware layer in your stack, buy CMR.

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Frequently asked questions

Is the Ultrastar HC690 32TB CMR?

No. WD lists the HC690 family as SMR/UltraSMR.

Which 32TB HC690 variants exist?

WD lists WSH723220AL4201, WSH723220AL4204, WSH723220ALN601, WSH723220ALN604, WSH723220ALN6L1 and WSH723220ALN6L4 across SAS/SATA, security and power-disable variants.

Is HC690 32TB a drop-in replacement for Exos 32TB?

No. Exos 32TB in DatacenterDisk's tracked row is a CMR Seagate enterprise drive, while HC690 is WD UltraSMR/SMR and needs compatible host behavior.

Should I buy purely by the lowest price per TB?

No. Price per TB is the first screen, not the whole decision. Match recording method, interface, bay count, firmware support, warranty position and rebuild risk before accepting the cheapest row.

Sources

Specification claims on this page were checked against the pages below on 1 September 2026. Where a widely-repeated figure did not survive that check, we report what the source says now and say so in the text rather than repeating the familiar number.

  1. Western Digital - Ultrastar DC HC690 product page (WesternDigital.com, 2026)
    Used for: HC690 30TB/32TB model-number variants, SMR recording, SATA/SAS options, 550TB/year workload and 5-year warranty
  2. Western Digital - Ultrastar DC HC690 data sheet (WesternDigital.com, October 2024)
    Used for: WSH723200/WSH723220 model families, 30TB/32TB SMR, SATA 6Gb/s and SAS 12Gb/s, 512MB buffer, 7200 RPM, 260MB/s and 269MB/s maximum sustained transfer rates, power and sector-format notes
  3. Western Digital - SMR HDD technology for AI data centers (blog.WesternDigital.com, 2025)
    Used for: UltraSMR context, host-managed SMR stack requirements and suitable controlled-write workloads
  4. Zoned Storage - Shingled Magnetic Recording hard disks (ZonedStorage.io, 2026)
    Used for: sequential-write-required zones and ZBC/ZAC host-management behavior for host-managed SMR disks
  5. DatacenterDisk Research - Live price and stock database (DatacenterDisk.com, Live)
    Used for: current product availability, live prices, stock state, condition labels and cost-per-terabyte calculations