Pet hair is the single hardest debris type for a robotic vacuum to deal with — it tangles around brush rollers, escapes side brushes, and embeds into carpet pile in a way that food crumbs and dust never do. We standardized a pet-hair test rig to compare the two flagships in this category: 5 g of golden retriever hair (collected from one weekly brushing session of a single donor dog) distributed evenly across three flooring types: hardwood, low-pile carpet (Berber, ~5 mm pile), and mid-pile carpet (residential cut-pile, ~12 mm pile).
Methodology
- Test area: 8 m² zone per surface, marked with painter's tape.
- Hair distribution: weighed into 1 g portions, distributed by sieve at 40 cm height for consistent dispersion.
- Pickup measurement: pre-test weigh of empty dustbin (sub-gram precision scale, 0.01 g resolution), post-test weigh, delta is captured hair. We also visually inspected each surface and the brush roller after each pass.
- Robot settings: Max suction mode, single pass, mopping disabled, side brushes engaged.
- 5 runs per robot per surface, mean reported.
Pickup percentage (higher is better)
| Surface | Roborock S9 MaxV Ultra | Dreame X40 Ultra |
|---|---|---|
| Hardwood | 99% | 98% |
| Low-pile carpet | 96% | 94% |
| Mid-pile carpet | 91% | 87% |
On hardwood both robots are essentially tied — the difference is within measurement noise. The Roborock pulls ahead on carpet thanks to 22,000 Pa max suction (vs the X40 Ultra's 12,000 Pa) and a higher-torque main brush motor that maintains suction force even as the pile resists airflow.
Brush wrap test (after 5 sessions, lower is better)
Both robots advertise "anti-tangle" rubber-and-bristle main brushes. After 5 cumulative sessions of pet-hair pickup:
- Roborock: 0.4 g of hair wrapped around brush axle
- Dreame: 0.6 g of hair wrapped around brush axle
Neither was unmaintainable — both cleared with the included brush tool in under 60 seconds — but the Roborock's narrower brush bearings showed slightly less hair migration to the axle.
Side brush hair scatter
A common failure mode: side brushes fling pet hair away from the suction path. We marked starting hair piles and counted "scatter events" (hair displaced more than 30 cm from intended path):
- Roborock: 11 scatter events across 15 test runs.
- Dreame: 18 scatter events across 15 test runs (single 3-armed side brush is slightly more aggressive).
Noise during pet-hair mode
| dB(A) at 1 m | |
|---|---|
| Roborock S9 MaxV Ultra (Max) | 67 |
| Dreame X40 Ultra (Max) | 65 |
Both robots stay below conversation-disruption levels at normal viewing distances; the Dreame edges ahead on noise by ~2 dB. In auto mode (medium suction), both drop to 59–61 dB.
Carpet vs hardwood — which to optimize for
If your home is predominantly hardwood with rugs, both robots are excellent picks. If your home is 50%+ carpet, the Roborock's suction advantage compounds across daily cleaning and ends up with measurably cleaner carpet over a month.
Long-term pet-hair maintenance
Both robots' self-empty bases (Roborock RockDock Ultra, Dreame DocStation Ultra) handle pet-hair-laden dustbins without clogging in our 60-day stress test. Plan for a $40/year bag spend on either. The Roborock's bag has slightly better sealing — no detectable dust release on bag changes.
Verdict
On hard floors the two are essentially tied; pick on noise or app polish. On carpet, the Roborock's higher suction (22,000 Pa vs 12,000 Pa) shows in the pickup numbers — 4 percentage points on mid-pile is the difference between "looks clean" and "actually clean" after a single pass. The Dreame edges ahead on noise (~2 dB) and on threshold-climbing ability (the X40's lifting mop and 60 mm threshold are class-leading).
See the full Roborock S9 MaxV Ultra vs Dreame X40 Ultra comparison or our best robot vacuums 2026 guide for the broader category.