WD Ultrastar DC HC690: What WD States About Its 30TB and 32TB SMR Drive

Ultrastar DC HC690 specifications from WD's data sheet

WD calls the HC690 the world's first 11-disk HDD platform and gives it a capacity of up to 32 TB in SMR, shingled magnetic recording. The data sheet, dated October 2024, prints four variants: 30 TB and 32 TB, each in SATA 6 Gb/s and SAS 12 Gb/s. These are the figures it gives:

The sustained transfer rate is the same on SATA and SAS at each capacity, so choosing SAS does not buy sequential speed on this sheet; it costs 0.3 W at idle instead. WD prints the idle efficiency itself, at 0.18 W/TB for SATA and 0.19 W/TB for SAS at 30 TB and 0.17 and 0.18 W/TB at 32 TB. It calls the HC690 a high-capacity helium drive and credits its HelioSeal technology's stable internal environment with one of the lowest power profiles in the industry.

WD marks the failure rate as projected: final MTBF and AFR specifications will be based on a sample population and are estimated by statistical measurements and acceleration algorithms, and the ratings do not predict an individual drive's reliability. WD's en-GB product page adds the physical figures, 146.81 mm by 101.6 mm by 26.16 mm and 670 g, an endurance figure of 550TB a year as the page labels it, and a 5-Year Limited Warranty. The warranty is WD's statement as the maker; what a seller passes on with a particular listing is a separate matter.

Is the Ultrastar DC HC690 SMR or CMR?

SMR. The recording technology row on WD's sheet reads SMR on all four variants, and we have not found CMR stated for any of them. WD ties the capacity to its UltraSMR and energy-assisted Perpendicular Magnetic Recording (ePMR) technologies. For contrast, WD's HC590 sheet states capacities up to 26 TB with CMR, while the HC690 sheet prints SMR at 30 and 32 TB.

SMR drives come in more than one zone model, and that matters more than the label. The Zoned Storage documentation describes the drive-managed model as one that handles the SMR sequential-write constraint internally, in the disk firmware, and provides a backwards-compatible interface to the host. We have not found a WD document that states which zone model the HC690 uses: in the data sheet and the en-GB product page we found no statement that it is host-managed, host-aware or drive-managed. So we do not tell you that it will behave like an ordinary drive in your system, nor that it will not.

In practice, if your server, NAS or RAID controller was set up for CMR drives, confirm with WD or your system vendor that it supports the HC690 before you order one. If you need CMR, WD's HC590 sheet states it at up to 26 TB: see Ultrastar DC HC590.

HC690 model numbers decoded

WD prints a key for the WSH7232 pattern. The digits after WSH7232 give the capacity: 00 is 30 TB and 20 is 32 TB. The xx pair is the interface, and the key gives N6 as 4Kn SATA 6 Gb/s and 42 as 4Kn SAS 12Gb/s. The y position records the Power Disable Pin 3 status, and z is the data security mode: 0 for Instant Secure Erase, 1 for SED TCG-Enterprise with crypto scramble erase, 4 for Base (SE) with no encryption and overwrite-only sanitisation, and 5 for SED-FIPS.

One part of the sheet does not agree with another. The model key calls both interface codes 4Kn, yet the specification table lists both 512e and 4Kn sector sizes. We have not found anything on the sheet that reconciles the two, so we print both rather than choose. If your system needs 512e, ask the seller or WD which you would receive before buying.

WD's en-GB product page shows how a complete string reads: WSH723200ALN6L1, listed with TCG security. By the key, 00 makes it the 30 TB model, N6 the SATA interface and the final 1 the SED TCG-Enterprise mode. We have not found a WD short part number for the HC690 on either the data sheet or the product page, so a listing that gives only a short code cannot be checked against WD's documents. Search a listing for the full WSH7232 string instead.

OptiNAND, ArmorCache and HelioSeal on the HC690

• OptiNAND: WD says it uses integrated iNAND embedded flash to perform key housekeeping functions, freeing up more capacity and improving overall drive performance.
• ArmorCache: a choice of write cache disabled (WCD) mode for increased random write performance, or write cache enable (WCE) mode to protect cached data if the power is cut by an Emergency Power Off or an unexpected loss.
• HelioSeal: WD's helium sealing, which it says gives the drive a stable internal environment and a low power profile.

Those are WD's own descriptions. We have not found a WD document that puts a figure on what OptiNAND or ArmorCache change for this drive, so we print none.

Ultrastar DC HC690 price on Amazon.co.uk

Our HC690 table holds no listings right now. The table matches listings that name the HC690 or a WSH7232 model; when it is empty, the alternatives table shows the nearest drives in stock. Any price it shows is pounds sterling inc VAT, with a Buy on Amazon button on the row.

If you came here for 30 TB, 30TB hard drives compares what is on offer at that size from all makers. For the CMR Ultrastars below it, see Ultrastar DC HC580, WD Ultrastar 24TB and 26TB hard drives, or the whole family on WD Ultrastar.

In-stock alternatives

None of these is the product this page covers: they are what is in stock on Amazon.co.uk beside it right now. Each row says why it is listed. Check the interface, form factor and part number against your system before buying.