Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Dreame - X40 Ultra | Roborock - Saros Z70 |
|---|---|---|
| Suction | 12000 Pa | 22000 Pa |
| Battery life | 210 min | 180 min |
Between the X40 Ultra and Saros Z70, the X40 Ultra comes out ahead in battery life, while the Saros Z70 wins on suction. Overall, the X40 Ultra scores 83.9 and the Saros Z70 scores 88 on our Mars Score.
Which should you buy?
The Saros Z70 edges ahead on the Mars Score (83.9 vs 88), but the 4.1-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the X40 Ultra if you care most about battery life. The biggest gaps in its favor are battery life. The single most decisive one: Battery life — 16.67% more. 210 min vs 180 min.
Pick the Saros Z70 if you care most about suction. Its strongest claims are suction. The single most decisive one: Suction — 83.33% more. 22000 Pa vs 12000 Pa.
Both ship with comparable mopping, lidar, self-empty base, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Dreame - X40 Ultra or Roborock - Saros Z70?
Roborock - Saros Z70 leads the current Mars Score by 4.1 points.The more useful decision is the trade-off behind that result: compare suction, battery life against the way you will actually use the product.
Choose Dreame - X40 Ultra if…
Dreame - X40 Ultra has the measurable edge on battery life min.
Choose Roborock - Saros Z70 if…
Roborock - Saros Z70 has the measurable edge on suction pa.
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 Dreame - X40 Ultra wins
- ▲Battery life — 16.67% more. 210 min vs 180 min.
Why Roborock - Saros Z70 wins
- ▲Suction — 83.33% more. 22000 Pa vs 12000 Pa.
Spec comparison
Cleaning
| Spec | Dreame - X40 Ultra | Roborock - Saros Z70 |
|---|---|---|
| Suction | 12000 Pa | 22000 Palead |
| Mopping | true | true |
| Water tank | 270 ml | 270 ml |
| Dustbin | 350 mllead | 300 ml |
| Carpet detection | true | true |
Navigation
| Spec | Dreame - X40 Ultra | Roborock - Saros Z70 |
|---|---|---|
| Lidar | true | true |
| Camera navigation | true | true |
| AI obstacle avoidance | true | true |
| Max climb | 60 mmlead | 40 mm |
Autonomy
| Spec | Dreame - X40 Ultra | Roborock - Saros Z70 |
|---|---|---|
| Battery life | 210 minlead | 180 min |
| Self-empty base | true | true |
| Self-wash mop | true | true |
| Self-dry mop | true | true |
| Noise | 65 dB | 65 dB |
Frequently asked
Which has stronger suction, X40 Ultra or Saros Z70?+
Saros Z70 delivers 22000 Pa vs 12000 Pa.
Do X40 Ultra or Saros Z70 mop?+
Both can mop.
Which has a self-emptying base, X40 Ultra or Saros Z70?+
Both ship with a self-emptying base.