Roborock S8 MaxV Ultra vs Dreame X40 Ultra (2026)

Roborock S8 MaxV Ultra vs. Dreame X40 Ultra: A Real-World Comparison (2026)

If you've narrowed your robot vacuum shortlist down to the Roborock S8 MaxV Ultra and the Dreame X40 Ultra, you're already thinking at the right level. Both are flagship, fully-autonomous floor cleaners with self-emptying, self-washing docks, powerful suction, and serious mopping chops. They're also strikingly similar in price and features, which makes choosing between them genuinely difficult — unless you dig into the data.

We've pulled together hands-on test results, expert reviews from PCMag and ZDNET, and in-depth video testing by robot vacuum specialist Jamie Andrews to settle this debate. Here's what the numbers actually show.

Specs at a Glance

Vacuuming Performance: Who Actually Cleans Better?

Hard Floors

On tile and hard flooring, Jamie Andrews ran a standardized cat litter test and found both robots virtually neck and neck. The S8 MaxV Ultra picked up 122 g out of a total 130 g deposit — that's 94%. The X40 Ultra with its stock brush? Exactly the same: 122 g, 94%. You cannot separate them on hard floors under normal conditions.

However, if you're willing to spend a bit extra on the optional Dreame TriCut brush (sold separately on Amazon), the X40 bumps its hard floor pickup to 125 g — a 96% capture rate. That accessory gives Dreame a meaningful edge for households with heavy dust or pet hair on hard surfaces, even if it's not a stock advantage.

Carpet Performance

Carpet is where we start to see separation. In Andrews' rice-on-carpet test, the Dreame X40 Ultra achieved a perfect score — 100% of the rice (all 54 g) recovered. The Roborock S8 MaxV Ultra came in at 98%, picking up 53 g. That single gram difference translates to a meaningful real-world distinction: over time, on thicker rugs and carpets, the X40 consistently pulls more debris out of pile.

Worth noting: if you install the TriCut brush on the X40 before running it on carpet, performance actually drops to 94% (51 g). The TriCut upgrade is a hard-floor enhancement, not a carpet upgrade — don't use it if carpet is your priority.

Overall verdict on vacuuming: Dreame X40 Ultra wins on carpet, it's a tie on hard floors. The X40 is the stronger all-around vacuum performer.

Mopping: Where the Design Philosophies Diverge

This is the most philosophically interesting difference between these two robots. Roborock and Dreame have taken divergent approaches to the mop-on-carpet problem, and which one you prefer will depend heavily on your floor plan.

Roborock's Approach: Lift and Scrub

The S8 MaxV Ultra lifts its mop pads off the floor when it detects carpet, preventing cross-contamination. It also features a secondary edge mop and a built-in detergent compartment — so the machine is consistently applying a cleaning solution rather than just water. PCMag noted that Roborock has layered in these self-maintenance features progressively: the S7 MaxV Ultra had camera functionality, the S8 Pro Ultra added hot air drying, and the S8 MaxV Ultra brings it all together — voice control, edge mopping, and the detergent compartment — in one package.

Dreame's Approach: Leave the Mops Behind

The Dreame X40 Ultra takes a more radical approach. Its mop pads are fully detachable, and the robot can drop them off at the base station before heading onto carpeted areas. That means carpets get zero mop contact — not lifted mops hovering an inch above, but no mops at all. For homes with significant carpet coverage, this is arguably the cleaner solution. The X40 also has a lifting side brush, giving it better edge-mopping reach without a separate physical attachment.

ZDNET named the Dreame X40 Ultra their pick for the best robot vacuum and mop combination, citing its extensive feature set and overall cleaning versatility. The detachable mop system was a major factor in that assessment.

Design, Docks, and Day-to-Day Living

The Base Stations

Both docks handle auto-empty, auto-wash, and auto-refill duties. ZDNET described the X40 Ultra's base station as visually appealing — a grooved front panel with gold accents gives it a more premium feel than most robot vacuum docks, which tend to look like squat white appliances. The Roborock dock is more utilitarian in appearance but includes hot air mop drying, a feature Roborock introduced with the S8 Pro Ultra generation and carried forward here.

Brush Roll Design

The S8 MaxV Ultra is the only one of these two with dual brush rolls — a meaningful advantage for households with pets or long hair. Dual rollers distribute the workload and reduce the chance of hair tangling on a single bar. Roborock has also built a concealed scraper into the dual-roll system to keep it cleaner between maintenance sessions. If hair tangling has been a persistent problem for you with past robot vacuums, this is a real differentiator worth factoring in.

Everyday Maintenance

Both robots are engineered for minimal human intervention. Auto-empty, auto-clean, auto-refill — you should be going weeks without touching either machine in typical use. The Dreame's detachable mops do mean slightly more physical interaction when the dock is managing its cycles, but it's not meaningful in practice.

Navigation, Software, and Smart Features

Obstacle Avoidance

This is an area where the testing data is more nuanced. PCMag noted that the Roborock S8 MaxV Ultra's obstacle avoidance "falls a bit short of more affordable competitors," specifically calling out the Ecovacs Deebot X2 Omni — a robot that retails for $300 less — as better at navigating around objects. That's a notable criticism at a $1,799.99 price point. Andrews' testing highlighted that both the X40 and the S8 MaxV have capable obstacle avoidance, but neither is the class leader.

Voice Control

The S8 MaxV Ultra includes a built-in voice assistant — Roborock calls it "Hello Rocky." You can start, stop, pause, and query the robot by voice without reaching for your phone. The Dreame X40 Ultra has no equivalent. For users who want seamless smart home voice integration without relying on a third-party speaker setup, this is a genuine quality-of-life advantage for Roborock.

App and Mapping

Both robots use LiDAR-based navigation and offer detailed room mapping, zone cleaning, and scheduling. ZDNET noted that the Dreame X40 Ultra's app setup — via the Dreamehome app — was generally smooth, with occasional connection hiccups that resolved with a force-quit and relaunch. Roborock's app is similarly mature and reliable. Neither stands out as dramatically superior in software; both are capable, polished experiences.

How They Stack Up Against the Broader Market

At these price points, you're not just comparing two robots — you're asking whether either justifies its premium. PCMag gave the win to the Ecovacs Deebot X2 Omni as their Editors' Choice, noting better mopping and vacuuming performance at $300 less than the S8 MaxV Ultra. That's worth considering if budget flexibility matters.

On the other end, if you want something more affordable with solid performance, options like the Roborock Q Revo MaxV or the Narwal Freo X Plus offer competitive cleaning at lower entry costs. And for users more concerned with vacuuming than mopping, the older Roborock S7 MaxV Ultra remains a capable machine at a substantially reduced street price.

That said, both the S8 MaxV Ultra and X40 Ultra are legitimate flagship-tier robots. If you want the best available and have the budget for it, either will outperform most of the market.

Verdict: Which Robot Vacuum Should You Buy?

The honest answer is that these two robots are remarkably matched — but they're not identical, and the right choice depends on your home.

Choose the Dreame X40 Ultra if:

• You have significant carpet coverage and want mops fully removed (not just lifted) before the robot runs on rugs
• You want better raw suction power (12,000 Pa vs. 10,000 Pa)
• Carpet vacuuming performance matters — 100% pickup in testing vs. 98%
• You're willing to invest in the optional TriCut brush for improved hard-floor performance

Choose the Roborock S8 MaxV Ultra if:

• You have pets or long-hair household members and want dual brush rolls to prevent tangles
• You want a built-in voice assistant for hands-free control
• You value the dedicated detergent compartment for consistent cleaning solution application
• You prefer Roborock's established ecosystem and track record

In most homes with a mix of hard floors and carpet, the Dreame X40 Ultra edges out the Roborock S8 MaxV Ultra on raw cleaning metrics. But the Roborock is not a weak choice — it's a feature-rich, thoughtfully designed machine that will satisfy the overwhelming majority of users. If dual rollers or voice control are priorities, don't let the carpet test numbers push you away from it.

Both are expensive. Both are worth it for the right buyer. The data is now in your hands.