Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Samsung - 990 PRO 2TB | Samsung - T9 Portable 2TB |
|---|---|---|
| Sequential read | 7450 MB/s | 2000 MB/s |
| Sequential write | 6900 MB/s | 1950 MB/s |
| Interface | PCIe 4.0 x4 | USB 3.2 Gen 2x2 |
Between the 990 PRO 2TB and T9 Portable 2TB, the 990 PRO 2TB comes out ahead in sequential read / sequential write, while the T9 Portable 2TB wins on interface. Overall, the 990 PRO 2TB scores 69.2 and the T9 Portable 2TB scores 64.1 on our Mars Score.
Which should you buy?
The 990 PRO 2TB edges ahead on the Mars Score (69.2 vs 64.1), but the 5.1-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the 990 PRO 2TB if you care most about sequential read / sequential write. The biggest gaps in its favor are sequential read, sequential write. The single most decisive one: Sequential read — 272.50% more. 7450 MB/s vs 2000 MB/s.
Pick the T9 Portable 2TB if you care most about interface. Its strongest claims are interface. The single most decisive one: Interface: USB 3.2 Gen 2x2 (vs PCIe 4.0 x4).
Both ship with comparable capacity, endurance (tbw), so those specs do not separate the two — focus on the differences below.
Bottom line: the 990 PRO 2TB is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: Samsung - 990 PRO 2TB or Samsung - T9 Portable 2TB?
Samsung - 990 PRO 2TB leads the current Mars Score by 5.1 points.The more useful decision is the trade-off behind that result: compare sequential read, sequential write, interface against the way you will actually use the product.
Choose Samsung - 990 PRO 2TB if…
Samsung - 990 PRO 2TB has the measurable edge on read mbps, write mbps.
Choose Samsung - T9 Portable 2TB if…
Samsung - T9 Portable 2TB has the measurable edge on interface.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Samsung - 990 PRO 2TB wins
- ▲Sequential read — 272.50% more. 7450 MB/s vs 2000 MB/s.
- ▲Sequential write — 253.85% more. 6900 MB/s vs 1950 MB/s.
Why Samsung - T9 Portable 2TB wins
- ▲Interface: USB 3.2 Gen 2x2 (vs PCIe 4.0 x4).
Spec comparison
Capacity
| Spec | Samsung - 990 PRO 2TB | Samsung - T9 Portable 2TB |
|---|---|---|
| Capacity | 2000 GB | 2000 GB |
Performance
| Spec | Samsung - 990 PRO 2TB | Samsung - T9 Portable 2TB |
|---|---|---|
| Sequential read | 7450 MB/slead | 2000 MB/s |
| Sequential write | 6900 MB/slead | 1950 MB/s |
| Interface | PCIe 4.0 x4 | USB 3.2 Gen 2x2lead |
| Form factor | M.2 2280 | Portable USBlead |
Endurance
| Spec | Samsung - 990 PRO 2TB | Samsung - T9 Portable 2TB |
|---|---|---|
| Endurance (TBW)ⓘ | 1200 | 1200 |
| Warranty | 5 yrs | 5 yrs |