SATA SSDs

SanDisk Ultra 3D 2 TB, five years and a claim of constant performance vs Western Digital WD Blue SA510 2 TB, with two bullets spent on subscriptions

The same headline speed twice — so what separates two 2 TB drives that agree on it?

Both of these print 560 MB/s in the title, and from there they diverge in exactly opposite directions. The SanDisk Ultra 3D repeats that one figure three times and states a five-year limited warranty. The WD Blue SA510 gives a second figure of 520 MB/s for writing and states no term of any length, while spending two of its five bullets on a bundled subscription.

SanDisk Ultra 3D 2 TB internal 2.5-inch SATA solid-state drive in black

SanDisk Ultra 3D 2 TB, five years and a claim of constant performance

Wins 1 of 11

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≈ $380 / £242 / 277 €

WD Blue SA510 2 TB internal 2.5-inch SATA solid-state drive

Western Digital WD Blue SA510 2 TB, with two bullets spent on subscriptions

Wins 2 of 11

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≈ $300 / £268 / 325 €

Line by line

Compared on	Ultra 3D 2 TB, five years and a claim of constant performance	WD Blue SA510 2 TB, with two bullets spent on subscriptions
Capacity	2 TB, in the title and in the box list	2 TB, in the title, the first bullet and the box list
Form factor	2.5-inch, printed twice	2.5-inch, printed twice
Height	Not published — inches twice, no millimetre figure	Not published — inches twice, on a drive offered as a laptop upgrade
Stated sequential read figure	Up to 560 MB/s, given as a transfer rate rather than named as reading	Up to 560 MB/s, named as reading in the fourth bullet
Stated sequential write figure	Not published — the same 560 MB/s is printed three times with no second rate beside it	Up to 520 MB/s, forty below the reading figure
Stated random IOPS	Not published	Not published
TBW rating	Not published, on a page that does publish a five-year term	Not published — long endurance is named in words with no total behind it
Stated MTBF	Not published — resilience and reliability are asserted instead	Not published
DRAM cache presence	Not published as memory on the drive — a caching technology is named by its trade name	Not published, either way
Controller family	Not published — the flash is named as three-dimensional and the page stops there	Not published — neither controller nor memory type is named
Warranty length	Five years, limited	Not published — no term appears, on a page that does state the length of a cloud trial

A tick means one listing published something the other did not, or published a better figure. It does not mean the product is better, and the column is not a score out of anything: a maker who says less loses lines here without losing a comparison. The two verdicts below are where the page is settled.

Which one, for whom

Buy the SanDisk Ultra 3D 2 TB, five years and a claim of constant performance

The Ultra 3D is the drive to take if the term matters to you: five years, limited, stated after the box list. Its weakness is arithmetic — 560 MB/s is printed three times and never joined by a rate for writing, so the direction that wears flash out is the one the listing declines to quantify. The claim of constant performance in the second bullet is an assertion, not a figure, and this site does not treat it as one.

Buy the Western Digital WD Blue SA510 2 TB, with two bullets spent on subscriptions

The SA510 is the more completely specified of the two on speed: 560 MB/s reading, 520 MB/s writing, both in the title, which is more than its stablemate manages. Against that, it states no warranty term anywhere — while finding room to state how long a bundled cloud subscription lasts. Two of its five bullets go to software. On a page with five bullets, that is the choice being made about what a buyer is told.

The questions that come up before an order

Why does the same 560 MB/s win for one drive and not the other?

Because the figures are not doing the same job. The SA510 names 560 MB/s as its reading rate and prints 520 MB/s beside it for writing; the Ultra 3D prints 560 MB/s as a transfer rate three times and never separates the two directions. One page distinguishes reading from writing and the other does not, so the reading row goes to the page that says which is which.

Neither drive publishes a TBW. Does that mean they are not rated?

It means the listing does not say. A total in terabytes written is a figure the maker publishes or does not; its absence from a product page is a fact about the page. This site records what is on the page and does not fill the gap with a figure from elsewhere.

The full reviews

SATA SSDs

SanDisk Ultra 3D 2 TB, five years and a claim of constant performance

2 TB · 2.5-inch · up to 560 MB/s · a named caching technology said to hold performance constant · five-year limited warranty · no write figure, no TBW, no MTBF

A two-terabyte drive with a five-year term and a named caching technology the page credits with constant performance, and which publishes no figure for writing and no endurance quantity.

Best for: A laptop or a desktop machine wanting two terabytes with a long term, where reading is the dominant job and the writing rate can be confirmed with the seller.

≈ $380 / £242 / 277 €

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SATA SSDs

Western Digital WD Blue SA510 2 TB, with two bullets spent on subscriptions

2 TB · 2.5-inch · up to 560 MB/s read · up to 520 MB/s write · endurance described in words · two of five bullets about bundled software · no TBW, no MTBF, no warranty term

A two-terabyte drive whose title carries both sequential figures and whose five bullets spend two of themselves on a cloud subscription and an imaging application, publishing no endurance quantity at all.

Best for: An upgrade from a spinning drive in a desktop machine or a laptop, where two terabytes at this interface is the requirement and the cloning tool is genuinely useful.

≈ $300 / £268 / 325 €

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Every price named in a summary was read on the date that review carries. What a shop asks today is shown beside the product, and it moves.