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NVMe SSDs

Samsung SSD 990 1 TB, a random write figure and a three-year term vs SanDisk WD_Black SN7100 1 TB, a drive its own page says is replaced

A written warranty and a random figure, or the faster sequential speeds?

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Both are 1 TB, Gen 4 and M.2 2280. The Samsung SSD 990 states 7,150 MB/s reading, 6,450 MB/s writing, 1,100,000 random write IOPS, four lanes and a three-year limited warranty. The WD_Black SN7100 states 7,250 MB/s and 6,900 MB/s — the fastest writer on the NVMe shelf — and opens its page with a notice that it has been replaced by the SANDISK Optimus GX 7100. Neither states an endurance rating.

Samsung SSD 990 1 TB internal M.2 NVMe drive on PCIe 4.0 with four lanes

Samsung SSD 990 1 TB, a random write figure and a three-year term

8.4/10

Wins 3 of 12

Check price

≈ $282

SanDisk WD_Black SN7100 1 TB NVMe solid-state drive on PCIe Gen 4

SanDisk WD_Black SN7100 1 TB, a drive its own page says is replaced

7.4/10

Wins 2 of 12

Check price

≈ $189

Port against port

Compared on SSD 990 1 TB, a random write figure and a three-year term WD_Black SN7100 1 TB, a drive its own page says is replaced
Capacity 1 TB 1 TB
Form factor code M.2 2280 M.2 2280
PCIe generation Gen 4, NVMe 2.0 Gen 4
Lane count Four Not published
Stated sequential read figure Up to 7,150 MB/s Up to 7,250 MB/s
Stated sequential write figure Up to 6,450 MB/s Up to 6,900 MB/s
Stated random IOPS 1,100,000 random write IOPS Not published
TBW rating Not published Not published
Stated MTBF Not published Not published
Warranty length Three years, limited Not published
DRAM cache Not published Not published
Heatsink Not published Not published
On Amazon.com, October 26, 2026 $282 $189

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 of the two, for which household

Buy the Samsung SSD 990 1 TB, a random write figure and a three-year term

Take the 990 for the written terms: three years of warranty, a random write figure and the Magician software for firmware. On October 26, 2026 it was the most expensive drive on the shelf, by about $93 over the SN7100, without faster sequential figures.

Buy the SanDisk WD_Black SN7100 1 TB, a drive its own page says is replaced

Take the SN7100 for speed — 100 MB/s more reading and 450 MB/s more writing — and power efficiency for laptops and handhelds. Its page states no warranty and says the drive has a successor, which is worth checking before ordering.

The questions that come up before an order

Does the SN7100's replacement notice matter?

It means this is the previous model. It still works the same; the newer Optimus GX 7100 is what SanDisk now points to.

Is a random IOPS figure worth paying for?

It describes small-file work — loading many small files, running an operating system — better than sequential speed does. Only the 990 publishes one here, so the comparison is one-sided rather than a measured win.

Each one, in detail

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.