Between the S8 Pro Ultra and S9 MaxV Ultra, the S8 Pro Ultra comes out ahead in several specs, while the S9 MaxV Ultra wins on suction and water tank. Overall, the S8 Pro Ultra scores 57.7 and the S9 MaxV Ultra scores 85.1 on our Mars Score.
Which should you buy?
The S9 MaxV Ultra is the clear pick on raw spec strength, leading by 27.4 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
The S8 Pro Ultra doesn't pull ahead on any single popular-comparison spec — its strengths sit in the spec table groups rather than the headline advantages.
Pick the S9 MaxV Ultra if you care most about suction and water tank. Its strongest claims are suction, water tank, noise.
Both ship with comparable mopping, lidar, battery life, so those specs don't separate the two — focus on the differences below.
Bottom line: the S9 MaxV Ultra is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Roborock - S8 Pro Ultra wins
- No decisive advantages.
Why Roborock - S9 MaxV Ultra wins
- ▲Suction — 266.67% more. 22000 Pa vs 6000 Pa.
- ▲Water tank — 66.67% more. 300 ml vs 180 ml.
- ▲Noise — 2.00 dB less. 65 vs 67.
Spec comparison
Cleaning
| Spec | Roborock - S8 Pro Ultra | Roborock - S9 MaxV Ultra |
|---|---|---|
| Suction | 6000 Pa | 22000 Palead |
| Mopping | true | true |
| Water tank | 180 ml | 300 mllead |
| Dustbin | 400 mllead | 350 ml |
| Carpet detection | true | true |
Navigation
| Spec | Roborock - S8 Pro Ultra | Roborock - S9 MaxV Ultra |
|---|---|---|
| Lidar | true | true |
| Camera navigation | true | true |
| AI obstacle avoidance | true | true |
| Max climb | 20 mm | 40 mmlead |
Autonomy
| Spec | Roborock - S8 Pro Ultra | Roborock - S9 MaxV Ultra |
|---|---|---|
| Battery life | 180 min | 180 min |
| Self-empty base | true | true |
| Self-wash mop | true | true |
| Self-dry mop | true | true |
| Noise | 67 dB | 65 dBlead |
Frequently asked
Which has stronger suction, S8 Pro Ultra or S9 MaxV Ultra?+
S9 MaxV Ultra delivers 22000 Pa vs 6000 Pa.
Do S8 Pro Ultra or S9 MaxV Ultra mop?+
Both can mop.
Which has a self-emptying base, S8 Pro Ultra or S9 MaxV Ultra?+
Both ship with a self-emptying base.
Spec-level deep dives
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