Roborock S8 Max Ultra
For buyers who can plumb in the dock and want a hands-off mopping robot that never needs its water tanks touched.
Amazon $599.99$599.99
The Roborock S8 Max Ultra is the better robot vacuum overall, rated 4.1 to 3.9. The Roborock S8 Max Ultra leads on dock. The Dreame X40 Ultra wins on mopping and navigation. The Dreame X40 Ultra costs $10 less ($589.99 vs $599.99).
Dreame X40 Ultra
Dreame’s 2024 flagship, now hard to find new; worth it only at a deep discount, as the X50 and L-series robots clean better.
Amazon $589.99$589.99
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Roborock S8 Max Ultra for dock (Self-empties the bin, washes the mop, hot-water mop wash, hot-air mop drying, doses detergent, optional water hookup vs Self-empties the bin, washes the mop, hot-water mop wash, hot-air mop drying, doses detergent).
- Choose the Dreame X40 Ultra for mopping (Dual spinning pads, leaves its mop at the dock for carpet, extends to edges vs Vibrating pad, lifts 20 mm, extends to edges) and navigation (LiDAR + camera vs LiDAR + 3D light).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every self-cleaning dock robot vacuum; a clear win is highlighted. How we rank explains each one.
| Factor weight | Roborock S8 Max Ultra | Dreame X40 Ultra |
|---|---|---|
| Overall rating | 4.1/5 | 3.9/5 |
| Cleaning 30% | 63 not yet tested; estimated from 19 tested Roborock robots and the median of the 70 tested robots | 37 measured 80% of sand from carpet, 75.5% of pet hair, some hair tangled (0.8) |
| Value 25% | 67 $600 | 68 $590 |
| Dock 20% | 100 Self-empties the bin, washes the mop, hot-water mop wash, hot-air mop drying, doses detergent, optional water hookup | 90 Self-empties the bin, washes the mop, hot-water mop wash, hot-air mop drying, doses detergent |
| Navigation 15% | 85 LiDAR + 3D light | 100 LiDAR + camera |
| Mopping 10% | 62 Vibrating pad, lifts 20 mm, extends to edges | 86 Dual spinning pads, leaves its mop at the dock for carpet, extends to edges |
Independent tests
Roborock S8 Max Ultra
No independent test published yet.
Dreame X40 Ultra
| Tested by | Carpet deep clean | Pet hair | Hair tangle (0 = none) | Area per charge | Conditions |
|---|---|---|---|---|---|
| Vacuum Wars | 80% | 75.5% | 0.8 | 1,287 sq ft | Embedded sand in medium-pile carpet; flattened 2.5 in pet hair on carpet, two runs; 7 in hair tangle on hard floor (0 = none wrapped). |
Specifications
| Roborock S8 Max Ultra | Dreame X40 Ultra | |
|---|---|---|
| Vacuum | ||
| Claimed suction | 8,000 Pa | 12,000 Pa |
| Main brush | DuoRoller Riser dual rubber brushes | Liftable rubber brush (TriCut Brush 2.0 sold separately) |
| Dustbin | - | 300 mL |
| Extending side brush | Yes | Yes |
| Mopping | ||
| Mop | Vibrating pad, lifts 20 mm, extends to edges | Dual spinning pads, leaves its mop at the dock for carpet, extends to edges |
| Mop lift | 20 mm | 10.5 mm |
| Leaves mop at dock | No | Yes |
| Extending mop | Yes | Yes |
| Water tank | - | 80 mL |
| Dock | ||
| Dock | Washes mop + empties | Washes mop + empties |
| Self-empties | Yes | Yes |
| Dust bag | - | 3.2 L |
| Washes mop | Yes | Yes |
| Hot-water wash | Yes | Yes |
| Hot-air drying | Yes | Yes |
| Detergent dosing | Yes | Yes |
| Water hookup option | Yes | No |
| Clean water tank | - | 4.5 L |
| Navigation & app | ||
| Navigation | LiDAR + 3D light | LiDAR + camera |
| Obstacle avoidance | 3D structured light (Reactive 3D) | RGB camera plus 3D structured light, recognises 120 object types |
| Climbs thresholds | - | 22 mm |
| Voice assistants | Alexa, Google Assistant, Siri Shortcuts | Alexa, Siri, Google Home |
| Build | ||
| Height | 3.8 in (97 mm) | - |
| Retracting LiDAR | No | - |
| Battery | 5,200 mAh | 6,400 mAh |
| Warranty | - | 3 years |
| Released | 2024-04 | 2024-04 |