The Best Cordless Vacuum Guide is reader supported. When you buy through the links in our site, we may earn an affiliate commission.

iRobot Roomba S9 vs. I7: Similarities and Differences Explained

When the first Roomba was introduced, it was an inefficient robot that required a lot of babysitting.

This is no longer the case with the Roomba S9 and I7.

These two new products from iRobot are the pinnacle of autonomous cleaning technology.

iRobot has been making these devices for over two decades and slowly have made incremental advances with each model.

Starting with the Roomba 980, iRobot now uses a better navigation system that’s more efficient and capable of cleaning larger spaces with better proficiency.

So which robotic cleaner is the better option? Do the upgrades in the S9 justify the astronomical cost? Or is the I7 a better deal?

Find out the answer to these questions and more in this review.

First, here’s a quick overview of the Roomba S9 vs. I7

Roomba I7
Power: 17 cfm
Run Time: 75 mins.
Deep Cleaning: 79% *
Dust Cup: 0.3 liters
Auto-Empty Bin: Yes
Smart Maps: Yes

Neato S9+
Power: 22 cfm
Run Time: 120 mins.
Deep Cleaning: 94.5% *
Dust Cup: 0.4 liters
Auto-Empty Bin: Yes
Smart Maps: Yes

Introduction to the Roomba S9 and I7

The S9 and I7 brought in two significant upgrades in the Roomba product line.

With the I7, it was the first Roomba with the “automatic dirt disposal system” where iRobot has a second vacuum inside the charging dock that empties the bin after it returns from a cleaning cycle.

Then in the S9, they ditched the round design and followed Neato’s D-shape structure.

Making this switch gives the Roomba S9 better-cleaning performance since it has a wider brush roll that spans the whole width of the robot.

Having a wider brush improves its edge cleaning over the I7. The S9 also has the “Clean Base” that automatically empties the dust bin.

Of course, these upgrades will come at a premium.

Roomba S9+ [with the Clean Base Dock]

Roomba S9 [without the Clean Base Dock]

Fortunately, iRobot gives you the option to purchase their products with or without the self-emptying system.

Folks who want to save money can opt for the non-plus variant that only comes with the robot.

Other than the addition of the clean base dock, both options are similar.

The clean base station can be bought separately and comes with a special dust bin with dirt disposal system. It is a significant upgrade that will cost several hundred dollars.

Advantages of the Roomba S9

  • Better at Edge Cleaning: The new D-shape design and the wider brush enables the S9 to perform better at cleaning edges and corners. Tests show that it does better at such.
  • Slower Spinning Side Brush: Another improvement that enables the S9 to clean better is the side brush that spins at a slower pace. The fast-spinning and stiff bristles side brush on the I7 and earlier models tend to create a bigger mess.
  • 30% Wider Extractors: Having the wider extractors allows this robot to cover more ground and better at avoiding tangles when cleaning hair.
  • More power: The Roomba S9 is the most powerful robot vacuum to date when it comes to airflow producing 22 cfm.
  • Better on Hard Floors: The strong airflow on low power and better-designed side brush give the S9 the edge on hard floor cleaning.
  • Will Deep Clean on Carpet Better: This model is one of a handheld of robotic vacuums that can pick up more than 90% of sand on medium-pile carpet.

Potential issues

  • Insanely Expensive: To give you some perspective on how expensive this robot is. It costs more than three high-end Dyson upright vacuums! That’s crazy!
  • Complaints about Software Issues: There were complaints about buggy software that affected how it navigates (e.g., gets stuck or lost).

Roomba I7+ [with Clean Base Dock]

Roomba I7 [without the Clean Base Dock]

Similar to the S9, the I7 also has two versions – the “plus” version with the clean base station and the entry-level option without it.

This model is the first Roomba with the automatic cleaning station that makes it truly autonomous.

Being the older option, iRobot has ironed out the software bugs as you’ll read in the reviews.

It retains the round shape that previous Roomba robots have. One reason why iRobot stuck with this design for its entire existence is its agility. Navigating around most furniture won’t be an issue.

Advantages of the Roomba I7

  • Less Expensive Alternative: The I7 is a few hundred dollars cheaper than the S9. Without the clean base dock, it’s a much better deal.
  • Better at Picking Up Large Bits of Dirt: This model does a better job at picking up Cheerios-sized dirt. One reason could be that the extractors are higher up. It comes at the cost of deep cleaning performance.
  • Autonomous Robot for Less: The Roomba I7+ provides the same hands-free convenience for much less than the S9+. If you don’t mind not having the bells, whistles, and better at cleaning embedded dirt pickup on carpet, the I7 will be an excellent choice.
  • An Excellent Option for Pet Owners: This robot has a fully-sealed system that keeps fine dust, dander, and other types of allergens at bay inside the bin. It is excellent at picking up pet liter and hair.

Potential issues

  • Still Expensive: Despite being the less expensive, the I7 is still more expensive than most other high-end robotic vacuums.
  • Won’t Deep Clean As Well: The less powerful motor and narrower extractors won’t pick up embedded dirt as well as the S9.
  • More tangles: Long hair will wrap up around the extractors and its axles. Make sure to regularly check the brushes if someone in your home has long hair.

Both robots have the same motor, navigation system and brush so expect the same performance.

The difference with the plus and non-plus versions is the upkeep.

There’s less babysitting with the “+” versions since a second vacuum in the dock will empty the bin.

Inside the clean base station is a bag that can hold up to “30 bins of dirt” according to iRobot.

So it’s a truly hands-free device that will keep the house clean with minimal babysitting.

Of course, there’s some maintenance work involved with regards to cleaning the brush roll and filters (more on that in a later section).

But the point is the Roomba I7, and S9 is the first truly automated robots smart enough to clean a whole level without any human involvement.

Roomba S9 Design

The Roomba S9 is a radical change from the I7. Gone is the round, puck shape design that iRobot used for the past few decades.

It’s now has a square front with a round backend – a D-shape design similar to the Neato D7.

I’m guessing iRobot did this to help their robots match the outstanding performance by their primary competitor.

In the middle is a gold disc that is the cover for the larger dust cup.

Behind the disc is the camera sensor that the S9 uses to map its location.

It has a matte charcoal finish that I like because it resists dirt better than something glossy.

Interface and Controls

The S9’s new shape necessitates a change in interface.

The three main buttons are now on the upper right of the robot, unlike in the previous version that sits at the middle.

It’s the same three buttons – home, clean, and spot. The rest of the features can be accessed through the Roomba Home App that you can download through Google Play Store or Apple’s App Store.

This Roomba retains the minimalistic simplicity that makes their products so popular.

Roomba I7 Design

The Roomba I7 retains the round design seen in earlier versions.

Right at the middle is the main camera that the I7 uses for mapping purposes. On the front is the IR sensor that helps it track the location of the charging base when it needs to dock.

This model has a semi-glossy, two-tone charcoal, and gray finish.

I’m not a big fan of glossy finishes because these are prone to fingerprints, but that’s my opinion.

Interface and Controls

The I7 has only had three buttons – home, clean, and spot.

Since this model has Alexa and an app, it does not need anything more than these. It’s a simple design that takes away the clutter.

You can use voice or schedule the robot through the app to clean.

How do the Roomba S9 and I7 clean?

There are several layers to unpack to understand how these robots clean.

It’s important to understand how it works so that you can maximize its functionality.

The first thing to look at is navigation.

How the S8 and I7 navigate?

These two robots have the same camera-based navigation that’s paired with iRobot’s new “Imprint Mapping Technology.”

What this term means is the maps that the robot creates through its sensors is saved in iRobot’s cloud servers.

A quick look at how the Roomba S9 navigates.

Having this feature allows these robots to plan a more efficient route in subsequent cleaning cycles because it has the maps saved.

It also gives these machines the ability to clean a specific room at a scheduled time.

This feature is usable with Alexa, so there’s an option to use voice and can say “Roomba, go clean the master’s bedroom.”

Both also have what iRobot calls “training runs” where the robot goes around the house with the vacuum motor shut off.

The purpose of this feature is for the robot to gather data about the home’s interior layout.

Since the motor is turned off, it will be able to scan your whole home without having to recharge since the vacuum motor is turned off.

Clean base charging station

If you get the “plus” option, both models will come with the “Clean Base” charging station that recharges and empties the dust bin.

It’s not an original design, but the Roomba I7 was the first robot vacuum with this feature to available for consumers.

This feature is very convenience because it takes the bin emptying chore out of the equation.

There’s no need to touch the robot for weeks on end, except for maintenance tasks such as checking the filters or brushes for any debris build-up.

With this device and the smart mapping technology gives consumers a lot of options such as cleaning certain rooms on specific days.

When the battery runs low, the robot will dock, recharge then resume where it left off making it possible for the Roomba S9 or I7 to clean larger homes.

A quick look underneath

Next, let’s look underneath these robots to see how it picks up dirt.

Here’s how the Roomba S9 and I7 look underneath. You can clearly see the design changes in the S9 with the wider brush and smaller side brush. The I7 basically retains the shape and layout of the 980 with some tweaks in the brush roll design.

Roomba S9

One look at the latest Roomba shows us the radical change that iRobot did.

Gone are the narrow extractors and the long, three-pronged side brush.

The main brushes are now in the front robot with a shorter side brush that has more prongs.

This brush spins at a slower pace, so it does not kick around dirt as much as the I7 or earlier Roomba models.

Here’s a close up look at the Roomba S9 side brush. Unlike the I7 brush that only has three prongs, the S9 has five shorter arms that spin slower.

The square front of the Roomba S9 plus the wider extractors (by 30%) brings better edge and corner cleaning to the table.

iRobot also adds a new 3D time-of-flight sensor at the front bumper that helps it navigate around tight areas.

This sensor helps the S9 “hug” the walls better, meaning it’ll go close so that it will clean these areas better than any Roomba robots before it.

Roomba I7

The Roomba I7 retains the round shape of its predecessors and has the same brush layout.

It has the narrower extractors located in the middle behind the side brush flanked by the two self-adjusting wheels.

Having a shorter cleaning path means it will take a bit longer to clean.

The Roomba I7 side brush has three prongs that are longer and spin at a more rapid pace than the S9.

The main side brush has three prongs on it that spin that a more rapid pace than the S9 which tends to scatter dirt around more on hard surfaces.

Despite this flaw, the I7 cleans quite well on surfaces like hardwood.

Dust Cup Comparison

Here’s the Roomba I7 dock.

When it comes to how much dirt it can hold, there isn’t much of a difference between these two robots.

The S9 with its redesigned that loads from the top can hold up to 0.4 liters while the I7 that slides out from the back has a 0.3-liter capacity.

If you decide to get the “plus” version the size difference will be irrelevant since the clean base dock automatically empties it.

How much power do the Roomba S9 and I7 have?

One important measure of how well a robotic vacuum will clean is the airflow.

Unfortunately, manufacturers don’t have a universal measure to gauge power, so for this section, let’s look at the airflow numbers.

An anemometer was used to measure airflow at the nozzle where the brush roll is.

Take note that there is always a margin for error for these types of tests, but it’s a good of comparison without any biases.

For the Roomba S9 and I7, it is a substantial difference.

The S9 on its high power setting produces up to 22 cfm of airflow and 8 cfm on low while the I7 has 17 cfm on its carpet boost mode (or high setting) and less than seven cfm on low.

Take note that the I7’ only has one power setting which is the auto mode where it automatically adjusts suction based on surface and the amount of dirt it detects.

Cleaning Performance

Let’s now look at how well these robots clean.

When it comes to picking up surface dirt, there isn’t much of a difference between the S9 and the I7.

But there are some quirks from the I7 you need to know about and how the improvements with the S9 addresses it.

Roomba I7

One of the biggest issues with the I7 is its lack of power in its low power setting. For some strange reason, it’s lower than the airflow numbers on the  Roomba 690 at seven cfm.

Hard floor cleaning

The I7 does a superb job at cleaning messes like this on the hardwood.

It adversely affects the I7’s performance, particularly at cleaning sand where it did do as well as the Roomba S9.

If you leave near the ocean and constantly have to deal with sand, the S9 will be the better option.

Other than sand, it was able to pick up all of the dirt in cleaning tests done – much better than the Roomba 980.

Another potential issue would be cleaning long strands of hair. In tests, the I7 only picked up 25% of the one gram of seven-inch human hair.  Most of it either wrapped around the axles or the extractors itself.

Short pet hair won’t be much of an issue though.

The longer pronged brushes spin at a much rapid rate which can toss dirt around more, but the I7 will eventually pick up dirt it scatters.

Carpet cleaning

The I7 did well in carpet cleaning tests with the fast-spinning side brush a non-issue on this surface.

One advantage it has over the S9 is its ability to pick up larger bits of debris without the crunching noise that the S9 has.

It won’t deep clean as well as the S9 because of the less powerful motor. In tests, the I7 was able to pick up only 79% of the 100 grams of sand on medium-pile carpet.

It is one of the best at doing so before the S9 came out.

Roomba S9

The S9, with its more potent motor, does offer advantages over the I7 in specific areas which we’ll look at in this section.

Hard floor cleaning

When it comes to cleaning normal household dirt such as dust, dander, cheerios, etc., the S9 and I7 produce similar results. Both have enough power for such a task.

However, when it comes to stuff like sand, the S9 with its power upgrade does a much better job.

The stronger airflow and the wider extractors will pick up more sand.

It is proven in cleaning tests where the S9 picked up nearly everything while leaving trace bits on the corners and edges.

The redesigned side brush, with shorter arms and more prongs, and slower rotation speed doesn’t scatter dirt. It does better at funneling dirt towards the main extractors.

Carpet cleaning

There isn’t much of a difference between the S9 and I7 in terms of surface dirt cleaning.

The benefit of wider brushes and a more powerful motor is seen in deep cleaning tests where the S9 got a very impressive score of 94.5% (average of two tests) when cleaning 100 grams of embedded sand on medium-pile carpet.

You’ll hear a crunching sound when it tackles extra-large stuff like Fruit loops, but it picks them up nonetheless.

Notable app features

The Roomba S9 and I7 use the iRobot Home app that unleashes the whole arsenal of goodies that make these products a modern-day Rosie.

Most of these are the same for both models.

  1. Keep Out Zones: It’s Roomba’s version as Neato’s no-go zones that act as a virtual wall that prevent the robot from going into “off-limit” areas. Initially, this feature is only available with the S9, but I7 users will benefit from it as well in the latest roll-out.
  2. Advanced Scheduled Cleaning: It is now possible to schedule the robot to clean a specific room at specific days. For example, on Mondays, Wednesdays, and Fridays, the robot can clean the living room.
  3. Imprint Smart Mapping: This technology is the ability of the robot’s software to save maps of an entire level of the home (up to 10). The robot can use this data to plan a better route and know exactly where it is.
  4. Zone Cleaning: It works well with the scheduling feature that tells the robot to clean specific rooms or areas.

Maintenance and Running Costs

Like with any other vacuum, there is a certain level of upkeep to keep it in tiptop shape.

Realize that these machines have various filters, sensors, and brushes that need periodic maintenance.

The amount of money spent will depend on whether you’ll get the “plus” or the basic version.

High-Efficiency Filter [once or twice a month]

Roomba S9 Filter

Roomba I7 Filter

iRobot recommends replacing it once every one to two months. Make sure to check it at least once a week for any dust build-up.

You can use a handheld vacuum to remove any stuck debris and extend intervals by a week or so.

These filters are not washable, so please avoid doing so to prevent voiding the warranty.

Clean Base Bags [depends]

Roomba S9 and I7 Clean Base Bags

Buying these bags is only applicable if you’re purchasing the “plus” variant with the Clean Base station. Intervals will depend on how often you run the robot and the type of dirt it cleans.

Pet owners obviously will have to replace it more often because pet hair and dander takes up a lot of space.

The good news there is a myriad of brands that sell bags for the S9 and I7. Both options use the same type of bag, so there’s less confusion.

Side Brush [depends]

Roomba S9 Side Brush

Roomba I7 Side Brush

Check the side brush for any hair that wraps around the base. The side brush of the S9 spins slower so it won’t there will be less wear versus the I7 side brush.

Rubber Extractors [depends]

Roomba S9 Extractors

Roomba I7 Extractors

The rubber extractors on the S9 and I7 will last longer than a more traditional brush in the 690.

Replacement parts are widely available just in case it wears out. As of this moment, replacement S9 extractors still isn’t available for sale, but there will be vendors selling these parts soon.

While iRobot may advertise it as maintenance-free, there is still a need to check it, especially at the axles where hair and dust can build up.

Replacement Battery [depends]

The Li-Ion batteries inside these robots will last at least a few years. These parts are better built and previous versions that use a Ni-Cad battery.

Another advantage of buying a Roomba over other brands is the availability of parts like the battery. Roomba provides easy access to the battery using simple tools.

The I7 and S9 being new, there aren’t a lot of options available, but there will be soon.

Full Bin Sensor [every two weeks]

Inside the dirt bin is a sensor that detects and fires a signal to the app if it is full. Clean this part at least once every two weeks.

Castor Wheel [depends]

One part that takes a lot of abuse is the castor wheel. This part is responsible for steering the robot. The I7’s castor wheel is at the front while the S9 sits at the rear portion.

iRobot recommends replacing it once a year, but with proper maintenance, I believe that it will last longer.

Make sure to regularly clean it using a clean microfiber towel to prevent any dirt build-up that could damage the bearings.


Around the robot is a bevy of sensors that help it move around furniture and pinpoint its exact location.

If any of these sensors get dirty, it compromises how these robots navigate, so use a clean microfiber towel to wipe the main camera sensor on top, and cotton buds tiny sensors around and underneath it.

Please visit this page for more information on how to maintain a Roomba.

The size difference between the Roomba I7 and S9

The Roomba S9 measures 12.5 wide and 3.5 inches tall while the I7 is slightly bigger measuring 13.34” wide and 3.63” tall.

So the S9 has a lower profile and will go underneath more furniture better than the I7. The narrower profile helps it fit between furniture legs less risk of getting stuck.

How long do the Roomba S9 and I7 run?

The Roomba S9 with its larger cell Li-ion batteries will run for up to 120 minutes on the low setting and 49 minutes on high. The Roomba I7 only has one power setting and it will run for up to 75 minutes.

On a side note, these numbers only matter if you’re getting the base version without the clean base station. With the “plus” version, it’s almost a non-factor because both variants have the recharge and resume feature.

Noise level comparison

Despite the bump in power, engineers in iRobot did a fantastic job with muffling the noise levels of both the I7 and S9.

The I7 only produces 62 decibels and the S9 tops out at 64 decibels. The difference is negligible, to be honest.

Other Roomba Comparisons

Roomba and Neato have a bunch of models in their product line. Find out how each one contrasts with the other plus also comparisons with other brands like the Neato.

Spec Comparison of the Roomba I7 vs. S9

Roomba I7+
Roomba S9+
Roomba I7
Roomba S9+
Self-Emptying Base
Recharge & Resume
Smart Mapping
Run time (Turbo mode)
75 mins.
120 mins.
Power (Turbo mode)
17 cfm
22 cfm
Power (Eco mode)
< 7 cfm
8 cfm
1-year limited
1-year limited

Which of the two offer better value?

There’s no doubt in my mind that the Roomba I7 and S9 are two of the best robotic vacuums available right now when you combine its efficiency and outright pickup-ability.

I understand that the price difference is substantial with the S9 easily being a few hundred bucks more expensive.

So is the premium worth it?

Let’s look at 4 reasons why you should consider the Roomba S9:

  1. Better at Embedded Dirt: The wider extractors and extra power make the S9 an excellent option for folks looking for something that can deep clean carpet. There’s no other robot available right now, aside maybe from the Neato D7 that can come close to the S9 in cleaning embedded dirt.
  2. Superior Edge Cleaning: Another benefit of the square frontend is its ability to clean edges better. It’s got a new sensor inside the bumper that makes it hug the walls and navigate around small spaces better.
  3. Does Not Tangle as Much: The larger beater bar resists tangles from longer strands of hair better than the I7. If you live with someone who has long hair, you may want to think of getting this over the I7.
  4. Better At Picking Up Sand: People who live near sandy areas will benefit from the ability of the S9 do so more efficiently.

Click here to learn more about the Roomba S9.

Now, let’s look at 3 reasons why you should consider the Roomba I7:

  1. Less Expensive: The Roomba I7 is a few hundred dollars cheaper than the S9. If the price is a primary concern then the choice is obvious.
  2. Same Efficient Navigation: Aside from the bumper sensor on the S9, the I7 has the same efficient navigation pattern of the S9. It has the same recharge and resumes feature along with the Smart Imprint Mapping system that saves maps in the cloud.
  3. Excellent at Surface Dirt: The one advantage the S9 has over the I7 is its ability to deep clean carpet. Aside from that the I7 and S9 are almost identical when it comes to surface debris pick up (aside from sand). If deep cleaning is not really a concern then save a few hundred bucks with the I7.

Click here to learn more about the Roomba I7.

To summarize here are the differences between the Roomba I7 vs. S9:

  1. Design: The S9 is the first Roomba to have the square shape front to fit in the wider extractors and new side brush. The I7 retains the round shape of the previous generation 980.
  2. Runs longer: The S9 will run for up to 120 mins on eco mode while the I7 runs for up to 75 minutes (it only has one power setting).
  3. Side brush: The S9 side brush has a smaller diameter with more tentacles and it spins at a slower pace than the I7. This prevents dirt from scattering on hard surfaces.
  4. Price: Buying the S9+ with the clean base station will be equivalent to buying more than three Dyson uprights. It is expensive. The I7, especially the non-plus version is way cheaper.
  5. Edge cleaning: The wide extractors and square front of the S9 allows it to clean edges better.

1 thought on “iRobot Roomba S9 vs. I7: Similarities and Differences Explained”

  1. Can I buy the cleaning tower for s9 later maybe 6 months after?

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.