Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Dreame - X40 Ultra | Roborock - S8 Pro Ultra |
|---|---|---|
| Suction | 12000 Pa | 6000 Pa |
| Water tank | 270 ml | 180 ml |
| Battery life | 210 min | 180 min |
| Noise | 65 dB | 67 dB |
Between the X40 Ultra and S8 Pro Ultra, the X40 Ultra comes out ahead in suction / water tank, while the S8 Pro Ultra wins on several specs. Overall, the X40 Ultra scores 83.9 and the S8 Pro Ultra scores 79 on our Mars Score.
Which should you buy?
The X40 Ultra edges ahead on the Mars Score (83.9 vs 79), but the 4.9-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 suction / water tank. The biggest gaps in its favor are suction, water tank, battery life, among others. The single most decisive one: Suction — 100.00% more. 12000 Pa vs 6000 Pa.
The S8 Pro Ultra similarly does not carry a headline advantage on the popular specs — look at the full table for category-specific deltas.
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 - S8 Pro Ultra?
Dreame - X40 Ultra leads the current Mars Score by 4.9 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 suction pa, water tank capacity ml, battery life min.
Choose Roborock - S8 Pro Ultra if…
Roborock - S8 Pro Ultra does not lead a decisive measured field here, so choose it for price, ecosystem, design, or availability when those matter more to you.
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
- ▲Suction — 100.00% more. 12000 Pa vs 6000 Pa.
- ▲Water tank — 50.00% more. 270 ml vs 180 ml.
- ▲Battery life — 16.67% more. 210 min vs 180 min.
- ▲Noise — 2.00 dB less. 65 vs 67.
Why Roborock - S8 Pro Ultra wins
- No decisive advantages.
Spec comparison
Cleaning
| Spec | Dreame - X40 Ultra | Roborock - S8 Pro Ultra |
|---|---|---|
| Suction | 12000 Palead | 6000 Pa |
| Mopping | true | true |
| Water tank | 270 mllead | 180 ml |
| Dustbin | 350 ml | 400 mllead |
| Carpet detection | true | true |
Navigation
| Spec | Dreame - X40 Ultra | Roborock - S8 Pro Ultra |
|---|---|---|
| Lidar | true | true |
| Camera navigation | true | true |
| AI obstacle avoidance | true | true |
| Max climb | 60 mmlead | 20 mm |
Autonomy
| Spec | Dreame - X40 Ultra | Roborock - S8 Pro Ultra |
|---|---|---|
| Battery life | 210 minlead | 180 min |
| Self-empty base | true | true |
| Self-wash mop | true | true |
| Self-dry mop | true | true |
| Noise | 65 dBlead | 67 dB |
Frequently asked
Which has stronger suction, X40 Ultra or S8 Pro Ultra?+
X40 Ultra delivers 12000 Pa vs 6000 Pa.
Do X40 Ultra or S8 Pro Ultra mop?+
Both can mop.
Which has a self-emptying base, X40 Ultra or S8 Pro Ultra?+
Both ship with a self-emptying base.