Toshiba MG vs WD Ultrastar: MG10 and MG11 Against HC550 to HC590 at 18TB to 24TB

Toshiba MG vs WD Ultrastar: matching the part numbers first

The two makers number their drives so differently that the first job is lining them up. Toshiba's 512e SATA models read MG11ACA followed by the capacity and TE: MG11ACA24TE down to MG11ACA14TE, with MG10ACA20TE and MG10ACA18TE in the older line. WD's Ultrastar sheets list short 0F part numbers by generation and size, with a model string such as WUH722020ALE6L4 beside some of them.

At 26 TB the HC590 stands alone: the MG11 overview stops at 24 TB. On the HC560, HC570 and HC580 sheets each size lists a Base SE model and an SED model, so two 0F numbers at one size are the same generation with different security options.

Toshiba MG vs Ultrastar at 18TB to 24TB: buffer, sustained rate and idle

Both makers print sustained transfer in MiB/s, so the column below uses that unit throughout; WD's sheets give MB/s alongside, shown in brackets. Each row is one model or one generation at one size, SATA.

Read in MiB/s, the MG11 leads at every matched size: 281 against 257 at 18 TB, 281 against 277 at 20 TB, 285 against 277 at 22 TB, and 295 against 284 and 274 at 24 TB. The older MG10 sits below the HC560 at 20 TB, 268 against 277. We have not found a document that states where on the disk Toshiba measures its figure, so treat a gap of a few MiB/s as an indication. The MG11's 1 GiB buffer is twice the 512 MB WD gives every generation here.

Idle power is the clearest gap. Every MG row sits between 4.16 W and 4.38 W, and every Ultrastar row between 5.5 W and 6.1 W, so at each matched size Toshiba's figure is lower by more than 1 W. The state names differ, Active Idle on Toshiba's sheets and Idle on WD's, and we have not found a document that defines them as the same.

Toshiba MG vs Ultrastar noise: decibels of sound power against bels typical

Toshiba prints acoustics as sound power, 20 dB idle and 32 dB seek on both the MG10 and MG11, and says the MG11 method is based on ISO 7779. WD gives each Ultrastar generation a single acoustic line in bels, typical, pairing an idle figure with an operating one, and we have not found the method behind it in any WD document.

On the HC590 sheet WD flips the order of that line to Operating/Idle, 3.2/2.5, where the four earlier sheets put idle first. Taken at its label, the HC590's idle figure is 2.5 bels, half a bel up on the HC580; the row above follows the label rather than guessing at a misprint.

We do not rank Toshiba MG against Ultrastar on noise. Toshiba's figures are sound power to ISO 7779, WD's are bels whose method we have not found, and seek is not the same test as operating. The safe readings are within each maker: the MG10 and MG11 match each other, and WD's idle figure is flat until the HC590.

Toshiba MG vs WD Ultrastar ratings and warranty

On ratings the two lines are matched. Toshiba gives MG10 and MG11 an MTTF of 2,500,000 hours with a 0.35% AFR and a rated annual workload of 550 TB per year, and its European MG Series page gives a 5-year limited warranty on the assumption that annual workload stays at or under 550 TB. On WD's side every generation here, HC550, HC560, HC570, HC580 and HC590, is rated for workloads up to 550 TB a year with a 5-year limited warranty.

WD's sheets carry a footnote worth applying to both makers: MTBF and AFR ratings do not predict an individual drive's reliability and do not constitute a warranty. Every Ultrastar generation on this page states CMR on its own sheet, and the MG10 overview describes MG10 as conventional magnetic recording, so recording technology does not separate them either.

Toshiba MG vs WD Ultrastar prices on Amazon.co.uk

New rows only, pounds sterling inc VAT, from Amazon.co.uk. A dash in the block below means one side has no in-stock row at that size right now.

On Amazon.co.uk many Ultrastar listings name only a 0F or WUH number, which is why the part-number map at the top matters. The Ultrastar table drops HC555 and SS530 titles and shows SATA and SAS together, with the interface on each row. The Toshiba table can also hold MG10-D rows at 8 TB and 10 TB, a different series. Recording technology prints only where a document names the part number.

Where each Toshiba MG and Ultrastar line goes from here

If one generation stands out from the tables, its own UK page goes further: Ultrastar HC550, HC560, HC570, HC580 and HC590, the WD Ultrastar range, Toshiba MG11 and the Toshiba MG series. Seagate's line against Toshiba is set out on Toshiba MG vs Exos.