Introduction
When looking at Roborock's lineup, the S8 MaxV Ultra and the Saros 20 Sonic represent two distinct generations of robot vacuum technology. The S8 MaxV Ultra launched in 2024 as a flagship model with impressive capabilities, whilst the Saros 20 Sonic arrived in March 2026 bringing significant technological advances to the table. Both models feature multifunction bases that handle washing and drying mops automatically, making them suitable for homes where hands-off maintenance is a priority.
The S8 MaxV Ultra targets users seeking comprehensive cleaning without constant intervention. The Saros 20 Sonic, being newer, pushes boundaries with enhanced suction power and refined navigation systems. For larger homes with varied flooring types, these specifications matter considerably when deciding which model fits your cleaning routine best.
Power and Suction
The difference in suction power between these two models is substantial. The S8 MaxV Ultra delivers 10,000 Pa, which handles everyday dust and debris effectively across hard floors and medium-pile carpets. The Saros 20 Sonic, however, reaches 36,000 Pa—more than triple the suction force. In practical terms, this translates to better performance on thick carpets and improved pickup of embedded dirt or pet hair.
Both models feature different approaches to the main brush. The S8 MaxV Ultra uses a double brush system, whilst the Saros 20 Sonic employs the DuoDivide Anti-Tangle design. This newer brush configuration channels hair towards the central suction area, reducing tangles significantly. For households with long-haired residents or shedding pets, this design makes maintenance less frequent.
The side brush setup also differs. The S8 MaxV Ultra includes an extensible side brush that reaches into corners but doesn't lift during mopping. The Saros 20 Sonic adds elevation capability and anti-tangle features to its extensible side brush, preventing hair buildup and avoiding interference when mopping. This refinement helps maintain consistent cleaning without manual intervention.
Mopping
Both models use vibrating mopping systems with sonic technology, but the Saros 20 Sonic brings several improvements. The S8 MaxV Ultra features a mini lateral mop for edge cleaning, whereas the Saros 20 Sonic offers full mop extension. This means the newer model gets closer to skirting boards and into tight spaces along walls.
Mop lift height varies between the two. The S8 MaxV Ultra raises its mops 20 mm when transitioning to carpets, whilst the Saros 20 Sonic lifts between 8-18 mm. The S8 MaxV Ultra's greater lift clearance provides better carpet protection, though the Saros 20 Sonic compensates with automatic mop removal at the base. When you want to vacuum only, the Saros 20 Sonic detaches its mops entirely, eliminating any contact with carpets.
Water temperature makes a noticeable difference in mopping results. The S8 MaxV Ultra uses cold water for floor mopping, whilst the Saros 20 Sonic employs warm water. Heated water dissolves sticky residues and greasy marks more effectively, particularly in kitchens or high-traffic areas. Both models detect dirt on mops and floors, triggering additional cleaning passes when necessary.
Navigation System
The S8 MaxV Ultra relies on a traditional LiDAR tower positioned atop the robot, adding to its overall height. The Saros 20 Sonic features retractable LiDAR that lowers when not needed, contributing to its slimmer profile. Both systems map accurately, but the retractable design allows the newer model to fit under more furniture.
Artificial intelligence capabilities differ markedly. The S8 MaxV Ultra recognises 73 different objects, which covers common household items like shoes, cables, and pet waste. The Saros 20 Sonic expands this to 300 objects, including curtain detection—a feature the older model lacks. This broader recognition prevents the robot from getting tangled in drapes or misidentifying obstacles.
Both models include dual AI cameras, 3D laser sensors, LED night vision, and remote camera access. The Saros 20 Sonic runs SmartPlan 3.0 compared to the S8 MaxV Ultra's SmartPlan 1.0, indicating more sophisticated cleaning strategies and route optimisation. In practice, this means fewer missed spots and more efficient coverage patterns.
Battery and Autonomy
Battery capacity sees an increase from 5,200 mAh in the S8 MaxV Ultra to 6,400 mAh in the Saros 20 Sonic. The older model provides 180 minutes of runtime, sufficient for homes up to around 250 square metres. The Saros 20 Sonic's larger battery should extend this further, though specific runtime figures weren't available in the data.
For larger properties or homes with multiple levels, the increased battery capacity reduces the likelihood of mid-clean recharging interruptions. Combined with the higher suction power, the Saros 20 Sonic maintains performance throughout extended cleaning sessions.
Smart Features
Obstacle clearance capabilities differ between the models. The S8 MaxV Ultra climbs obstacles up to 20 mm, handling standard door thresholds and thick rugs without issue. The Saros 20 Sonic is described as handling simple step climbing, though the exact measurement wasn't specified. Both models navigate typical household obstacles effectively.
Neither model includes a robotic arm. Both feature proprietary voice assistants alongside compatibility with external assistants like Alexa and Google Home, allowing voice control and integration into smart home routines.
Multifunction Base
Both bases handle automatic dustbin emptying, mop washing, and mop drying with hot air. They share 2.5-litre dust bags, 4-litre clean water tanks, and detergent dispensers. The key difference lies in base tray maintenance. The S8 MaxV Ultra requires manual cleaning of the wash tray, whilst the Saros 20 Sonic includes automatic tray cleaning with hot water.
This self-cleaning tray feature reduces hands-on maintenance considerably. The dirty water tank capacity differs slightly—3.5 litres on the S8 MaxV Ultra versus 3 litres on the Saros 20 Sonic. Neither model offers built-in plumbing connection or optional kits for water supply integration.
Hot air drying prevents mould growth and odours between cleaning sessions. The hot water mop washing removes stubborn dirt more effectively than cold water systems, keeping the mops genuinely clean rather than just damp.
Dimensions
Robot height represents the most significant dimensional difference. The S8 MaxV Ultra stands 103 mm tall, whilst the Saros 20 Sonic measures just 79.8 mm. This 23.2 mm reduction allows the newer model to slide under low-clearance furniture like beds, sofas, and cabinets that the taller model cannot access.
Both robots share a 353 mm diameter, typical for round robot vacuums. Base dimensions are nearly identical—409 mm wide and 470 mm tall—though the Saros 20 Sonic base extends 21 mm deeper at 440 mm compared to 419 mm. This slight increase shouldn't affect placement in most homes.
The S8 MaxV Ultra's dust container holds 270 ml, whilst the Saros 20 Sonic's capacity wasn't specified. Both include onboard water tanks, with the S8 MaxV Ultra holding 100 ml.
Real-World Usage
For homes with pets, the Saros 20 Sonic's anti-tangle brushes and substantially higher suction make daily hair management less demanding. The DuoDivide brush design specifically addresses the tangling issue that frustrates many pet owners. The enhanced object recognition also helps avoid pet toys and accidents more reliably.
In larger homes exceeding 200 square metres, the Saros 20 Sonic's increased battery capacity and more efficient navigation system complete cleaning cycles with fewer interruptions. The warm water mopping delivers noticeably better results on sticky kitchen floors or tracked-in grime.
The S8 MaxV Ultra's greater mop lift height suits homes with thick-pile carpets where complete separation between wet mops and carpet fibres matters. However, the Saros 20 Sonic's automatic mop removal provides an even cleaner solution for mixed flooring—the robot simply leaves the mops at the base when vacuuming carpeted rooms.
Low furniture presents a challenge for the S8 MaxV Ultra's 103 mm height. The Saros 20 Sonic's 79.8 mm profile accesses spaces the older model cannot reach, reducing manual spot-cleaning under beds and sofas. This proves particularly valuable in bedrooms and living areas with low-clearance furniture.
Conclusion: Which Should You Choose?
Choose the Roborock S8 MaxV Ultra if: you have thick carpets requiring maximum mop clearance, your furniture sits high enough to accommodate a 103 mm robot, and you're comfortable with occasional manual base tray cleaning. The 10,000 Pa suction handles typical household cleaning effectively, and the 180-minute runtime suits most homes. This model represents solid performance at what may now be a more competitive price point given the newer model's arrival.
Choose the Roborock Saros 20 Sonic if: you want the latest technology with triple the suction power, your home includes low-clearance furniture, you prefer warm water mopping for better results, or you have pets that shed heavily. The automatic mop removal and self-cleaning base tray minimise maintenance, whilst the expanded object recognition and SmartPlan 3.0 deliver more intelligent cleaning. For larger homes or those seeking maximum automation, the enhanced battery capacity and refined features justify the investment in this newer model.
