Roborock S8 MaxV Ultra vs Dreame X40 Ultra: Which Wins in 2026?

The Premium Robot Vacuum Showdown

At the $1,200–$1,500 price point, the robot vacuum market has converged around two flagship models: the Roborock S8 MaxV Ultra and the Dreame X40 Ultra. Both feature fully autonomous base stations that empty the dustbin, refill the mop water tank, and clean/dry the mop pads — making them as close to "set and forget" as robot vacuums have ever been. But under the hood, these machines take different engineering approaches to suction, mopping, and obstacle navigation that produce meaningfully different results in daily use.

Suction Power and Vacuuming Performance

The Dreame X40 Ultra claims a specification edge with 12,000 Pa suction versus the Roborock S8 MaxV Ultra's 10,000 Pa. In real-world carpet performance, this translates to a modest but measurable advantage on deeply embedded debris in high-pile carpet. On hard floors — the primary surface for most robot vacuum users — both machines clean comparably, with suction power rarely being the limiting factor at these levels.

RTINGS.com's independent testing places the Roborock S8 MaxV Ultra ahead on overall debris-pickup performance across a wider range of surface types. The edge comes from Roborock's brush roll design and side brush geometry, which is better optimized for maintaining consistent contact with irregular flooring transitions.

Mopping System Architecture

This is where Dreame has the stronger engineering story. The X40 Ultra uses dual rotating mop pads — two circular pads that spin at high RPM while applying downward pressure, creating a scrubbing action against stains and dried spills. The mopping heads lift fully off the floor when the unit transitions from hard floor to carpet, preventing carpet wetting. An optional plumbing kit allows permanent water line connection for truly autonomous refill without any human intervention.

Roborock's S8 MaxV Ultra uses a VibraRise mop system with two rectangular pads that vibrate at up to 4,000 times per minute. The vibration motion is effective for fresh spills and light staining, but user reports consistently rate it below the Dreame's rotating pad design for tackling dried, stuck-on messes. The mop pads also don't lift as aggressively on carpet transitions.

Navigation and Obstacle Avoidance

Both units use LiDAR-based SLAM navigation with comparable room mapping accuracy. The meaningful difference is in 3D obstacle avoidance. Roborock's ReactiveAI 3.0 system uses a combination of structured light and camera-based detection to identify and avoid objects including cables, socks, and pet waste. Dreame's 3D Obstacle Recognition uses a similar camera-assisted approach.

In independent tests, both systems perform comparably on standard obstacles. Roborock's longer track record in this category means its obstacle avoidance database (trained on more labeled scenarios) generally handles edge cases — unusual lighting, reflective floors, transparent objects — more reliably.

Battery Life and Efficiency

The Dreame X40 Ultra has a meaningful battery advantage: up to 194 minutes of runtime on a single charge versus the Roborock's 180 minutes — approximately 8% more. In a large home (3,000+ sq ft), this can mean the difference between completing a full clean in one pass versus requiring a mid-clean recharge on a particularly thorough cycle.

• Roborock S8 MaxV Ultra full review
• Dreame X40 Ultra full review
• iRobot Roomba Combo j9+ (alternative)
• All Self-Emptying Robot Vacuums

Price and Value

Both units retail in the $1,200–$1,500 range, with the Dreame X40 Ultra typically priced $50–$100 higher than the Roborock S8 MaxV Ultra at time of writing. The optional plumbing kit for the Dreame is an additional purchase but eliminates the last manual step in robot vacuum operation entirely.

Which Should You Buy?

Choose the Dreame X40 Ultra if: Mopping performance is your priority, you have large hard floor areas with frequent food spills or sticky messes, and the plumbing kit option appeals for a truly hands-off setup. The rotating mop heads are the best mopping implementation currently available in a robot vacuum.

Choose the Roborock S8 MaxV Ultra if: Vacuuming performance across mixed flooring is your primary concern, you have significant carpet coverage, or you value Roborock's more mature obstacle avoidance library and broader service network. See our full Robot Mop Combo rankings for all options.