Fractal Design Define S Window Mid-Tower Chassis Review

Fractal Design's Define S Window mid-tower case impresses Chad for the features it packs into its smaller size and what you get for the price.

Published Jun 19, 2015 3:11 PM CDT   |   Updated Tue, Nov 3 2020 6:59 PM CST
Manufacturer: Fractal Design
16 minute read time
TweakTown's Rating: 96%
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The Bottom Line

Fractal Design breaks its mold for the Define S! This chassis, while smaller, packs in a ton of options both in cooling and sound absorbing, and both versions can be had for less than $100.

Introduction, Specifications and Pricing

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Not that long ago, Fractal Design released a new chassis into their Define series of cases. With their Define series, they have had great success in the Define XL R2, the R4, and of course the R5, but this time around major changes are to be had with the latest design. Of course, along with the aforementioned designs, silence in operation was the key element of these cases, and even now that same idea is not lost, but at the same time, this latest design is made to keep up with the latest trends in chassis design to help keep the Define series on par and up to date with what customers are looking for in cases today.

While we do find the use of the ModuVent system as we have seen previously, and we also will find a solid front panel that these cases are well known for, and of course we also run into a water cooling ready chassis, that is not all there is to be had. If you want the utmost in silence, there is a solid side panel option with sound absorbing materials used to back them and deaden most noises that emanates from the standard chassis, they have also developed a version with a very large side panel window to allow users to take advantage of the new layout inside, as well as offering a great view of everything you have put into the chassis. On top of that, there is also the fact that this chassis is ODD-less, and does not offer a standard storage configuration that we are used to from Fractal Design either.

We are just starting to touch base on what this new chassis design offers, but we always try to save bits for the rest of the review. As we look at the latest Define S from Fractal Design today, you will see we do indeed get everything mentioned, but there is more to this chassis than what initially meets the eye. If you are a fan of Fractal Design cases, this has a lot of what you are used to already, yet still takes a wild turn from what we have seen in the past. For those that do not care for their previous designs, or just are not hip to what they offered in the past, this very well may be the chassis that is well worth the time it takes to get to know what they are all about. While this is a departure from the "classic" Fractal Design chassis, we feel that this chassis is on the bleeding edge of chassis design and is well worth your time to have a look at what this Define S is all about.

Fractal Design Define S Window Mid-Tower Chassis Review 01 |
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The chart provided is extensive, but we will help walk you through it all to get a good handle on what is going on in this Define S chassis. It is stated that it is capable of supporting Mini-ITX, Micro-ATX, as well as ATX motherboards, and offers seven expansion slots at the back. While the 5.25" bays are completely eliminated, we do find that the storage cages are gone as well. This design instead uses three trays behind the motherboard tray that are drilled to support either 3.5" or 2.5" drives, and a pair of 2.5" specific trays that can be found under the CPU cooler access hole, again behind the tray. If you opt for the solid panel version, you will have nine fan locations, but in the Window version we received, there are only eight. Of those locations, only two are filled from the factory with a pair GP14 140mm fans, one in the front, and one in the rear of the cases.

We also find that this chassis will support 180mm tall CPU air coolers, and while they do mention 180mm of PSU length, if you opt not to add fans or cooling to the floor of the chassis, that length can be stretched to 300mm of PSU power. As for the video cards, we are given 425mm of room, and if the fan configuration does not have a fan at the end of the card, you can increase that room to 450mm in total. We can also see that there is 20mm behind the motherboard tray, and 40mm near the front of the chassis to hide all of the wiring, and even offers Velcro straps to help maintain and route said wiring.

Things move to cooling at this point, and for a mid-tower chassis, this chassis has tons of options. The front of the chassis will support a trio of 140mm or 120mm fans, and without any bays there, access to them is superb. The rear of the chassis sticks to the standard one fan location, but the top of the chassis mimics the layout of the front of this design. The bottom of the chassis will also offer room for a single 120mm or 140mm fan, but also offers an additional surprise near the front of the chassis. They were also sure to provide dust filters for both the front of the chassis as well as under it to help keep the chassis free of dust with proper cleaning of said filters.

Water cooling capabilities really are what inspired this layout in the Define S. Here we see that the front of the chassis will house a 360mm radiator at maximum, but any radiator smaller as well, in both 140mm and 120mm versions, and it is stated that any thickness can be accommodated as well. Moving to the top of the chassis, we find that the largest radiator supported is a triple 140mm version as well as a triple 120mm radiator, and of course will allow anything smaller to fit as well, but they do make sure to mention that 55mm of thickness is the maximum here with fans included, as not to cause issues with the motherboard or other cooling options.

That leaves us with the back of the chassis and the bottom, which both will allow 120mm radiators, but the floor will also allow for a single 140mm radiator. That surprise we mentioned in the floor of the chassis, is that in front of the fan location, there are pre-drilled holes there to mount many DDC and D5 pump variations. Taking things one step further, they also offer adjustable reservoir brackets that can be installed that allows tube reservoirs to hang inside where the drive bays would typically be located.

As we shop around for this chassis, we do see that pricing varies depending on which version you would like to have. The solid side panel version of this chassis can be found for $79.99 requiring an additional $9.99 to ship that chassis. If you wish to opt for the windowed version we are bringing forth today, again over at, we found the chassis listed at $89.99, but for some reason this lighter chassis will set you back an additional $12.99 in shipping fees. We did look around at other outlets for this chassis as well, but currently, and likely due to the freshness of this chassis entering the market, availability is somewhat limited as to where it can be found.

On paper, this chassis offers a ton of features and options that will allow anyone from the first time builder right through those with huge pans of custom water cooling enthusiasts to take this mid-tower chassis and thoroughly enjoy what the Define S has to offer at a great price point. As always though, we wait to offer up any definitive statements about what is to be had until the end of the review, after we have tried out the options and seen what this chassis really brings to the table. We will say this however, the Define S is a departure from what most are used to, but we also feel that this is a great step forward in chassis design from Fractal Design, and well worth the time it takes to cruise through our images and see where they are going now.


Fractal Design Define S Window Mid-Tower Chassis Review 02 |

The packaging it typical of the industry, where plain cardboard is used with black screen printing used to offer the information. On the front, they offer the manufacturer and product naming above a large rendering of the Define S with a window. At the bottom, we find the Fractal design logo, that this is the windowed editions, and we also find the site address if more information is needed to be seen.

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The right side of the packaging then offers the Define S naming at the top, but this time the rendering offers a look at the internal layout of this design.

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As we move around to the back of the packaging, we find that the top is taken up with eight features found in the chassis, along with explanations of what they are or do. Moving lower on this panel, we find an exploded view of the chassis that shows everything from fans, filters, and removable bits all numbered to correspond with the features listed at the top.

Fractal Design Define S Window Mid-Tower Chassis Review 05 |

Then as we get to the last panel holding information, we find a very condensed version of the specifications and cooling system options. To be honest, if they offered what we covered earlier, it would take one of the larger panels to cover all of it, but with the address right on the box, even in the store, you can take a minute to see what all this chassis has to offer pretty easily.

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Internal packaging is also pretty much the industry standard. They cover both sides of the window prior to wrapping the entire chassis in a plastic liner to protect the surface of the chassis. To keep it from taking damage if someone were to drop this box on the way to your door, they went with the typical thick Styrofoam end caps.

The bottom bit of Styrofoam shows tape on the side, and this is due to the hardware being secured in a cutout of that cap, rather than allowing it to float around inside of the chassis in transit. All in all the packaging did its job, but the chassis was not exactly perfect upon removing all of this.

Fractal Design Define S Mid-Tower Chassis

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The front of the chassis is solid as you can see, and while there is a brushed metal finish, the bezel is entirely made of plastic. We also like that the bezel is completely unbroken with any naming or logo anywhere on it.

Fractal Design Define S Window Mid-Tower Chassis Review 08 |

At the front edge of the top of the chassis, we find the I/O panel. Here we find 3.5mm HD Audio jacks for headphones and a microphone. We also see a tiny reset button and a backlit power button, and to the right is a pair of USB 3.0 ports.

Fractal Design Define S Window Mid-Tower Chassis Review 09 |

The top of the chassis has ModuVent panels in place currently, which are just clipped into place. This makes them easy to remove if you plan to use this area for cooling, or leave them in place to help deaden the noises inside of this chassis.

Fractal Design Define S Window Mid-Tower Chassis Review 10 |

The window on the left side of the chassis is huge, and normally we would complain who needs a view of the bays, but with the Define S, there are no bays to be seen. Along with the chromes feet at the bottom, we also see that the front bezel is ventilated on the side to redirect any noises that may be had with optional cooling.

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As we move around to the back, we see the rear I/O and fan at the top, seven expansion slots, and room for the PSU at the bottom. We also noticed the door panel screws are captured so they do not come out, but we also noticed the panel on the left in this image is bent pretty badly right out of the box.

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The right side of the chassis is plain as can be with the solid panel in place. Just some textured paint to look at, but we do see that both side of the bezel are ventilated to allow as much air in as possible without breaking up the front bezel to do this.

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Under the chassis, we find small feet with rubber pads on them, pushed to the outside edges due to the removable fan filter that slides out the back of the chassis. We also see the hand hole in the bezel that allows access to the front of the chassis and is how you gain access to the removable filter there as well.

Inside the Define S

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As we removed the panels, with such a large window on the left, there is no sound absorbing materials, but after bending the right panel flat again, we flipped it over to see that the interior of that panel is covered edge to edge with it.

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With the front bezel pulled off the chassis, it exposed the dust filter which is held in place with tabs on one side and magnets on the left, allowing it to stay in place, yet still be easily removed for cleaning. This does need removed if you plan to change the stock cooling configuration.

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Inside of the chassis, it appears as if we had gutted it of the ODD and HDD bays, but this is how the Define S is designed. We do see that all of the wiring is run to the bottom and then through the grommet to keep it from flopping around and potentially scratching the window in transit.

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Two things we would like to point out here. The more obvious is that there is a single 140mm fan placed in the front of the chassis, but Fractal Design expects users to change to water cooling, so there is no point in adding to the cost here. The second thing is that the motherboard tray is bumped forward to the right of the motherboard, allowing more room behind it, but also causing an issue we found and will address in the final thoughts.

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At the top of the chassis, we see that the ModuVent panel are snapped into the fan holes, and are backed with more sound absorbing material. We also see near the front of the chassis that all of the wiring is run to the back high up on the panel, so that it will never hang in view through the window.

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The motherboard tray is labeled for ATX, Micro-ATX, and Mini-ITX layout of the standoffs, has a large cooler access hole, but uses only three grommets for wiring to the right and above the motherboard.

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In the floor, we find feet for a PSU and a gasket at the back, we find the location for additional cooling, and near the front, there are four oblong holes to allow a pump to be mounted there.

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Both fans are identical, and this 140mm fan also uses a 3-pin power connection for it.

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Behind the motherboard tray, to the left, we see a trio of HDD trays that work with 3.5" and 2.5" drives. We also see Velcro straps containing the wiring from the front I/O panel, and just under the access hole there are another pair of trays, this time specifically for 2.5" drives only.

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As far as the wiring is concerned, there is plenty of length for any build, it is all black in color, and we find the USB 3.0 connection, the switch and light wiring, and an HD Audio connection to round it all out.

Accessories and Documentation

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Part of what we find in the box tucked into the foam is what we have here. At the top, we find a bag of HDD screws to work with the trays, and next to that, we find another bag for 2.5" drive mounting and reservoir bracket screws. At the bottom, we see a bag of motherboard screws, and next to that, we see the standoffs and a socket to drive them in all the way.

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Also inside of that box we are given six wire tie straps to help out to maintain the wiring behind the motherboard tray. We also see the bag of PSU screws, and at the bottom of two brackets that screw into the right side of the motherboard tray to hold a reservoir.

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Along with all Fractal Design cases, we get a red insert that says not to return this product to the store. If you have any issues with your chassis, you should go directly to the manufacturer, not the point of sale. Also included is a thick, well written and illustrated manual to guide you and advise you through the build process.

Fractal Design Define S Window Mid-Tower Chassis Review 27 |

It is much easier to see how the reservoir brackets are used and where they connect to the chassis in this image, so rather than going on and on with the explanation of how it works, we used this image to do the talking for us.

Fractal Design Define S Window Mid-Tower Chassis Review 28 |

While we did go over the fan options, this image puts all of the questions to rest. This image is also for the non-windowed version of the chassis, so ours does not offer the side panel location shown in this image, but as for the rest of the fans, all of what is shown otherwise pertains to the windowed version as well.

Fractal Design Define S Window Mid-Tower Chassis Review 29 |

In case you were not exactly clear on the water cooling options afforded in this design, this single image makes it very clear. They even go as far as to show that the top can only house 55mm of radiator and fans, where in the rest of the chassis, thickness is of no concern.

Case Build and Finished Product

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With our standard testing gear in place, it is easy to see the amount of room afforded to be used for additional cooling, as well as seeing that the motherboard is set low enough in the chassis to not pose issues for radiators. As far as fit is concerned, we found no issues with installing the components, everything sort of falls into place with this design.

Fractal Design Define S Window Mid-Tower Chassis Review 31 |

The dust cover snapped right in, and the video card did not require us to force the back of the chassis inward to replace the thumbscrews either. As for the PSU at the bottom, with the gasket in play, you may need to go around the screws twice to secure it, but well worth the effort.

Fractal Design Define S Window Mid-Tower Chassis Review 32 |

With the build we use, even behind the motherboard tray, things are kept simple. With water cooling there are many more wires to contend with, but for our standard build, the Velcro straps contained all of our wiring without issue.

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The window is indeed large, but as we mentioned earlier, it affords a great view inside. When adding additional cooling and maybe some lighting, the view can only get better from here.

Fractal Design Define S Window Mid-Tower Chassis Review 34 |

From that same angle, once powered up, it is hard to tell things are running. If not for the view of the fans spinning inside of the chassis, we would have had to pull the door at this point to ensure it was indeed running.

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While there is a power LED that is blue, we also see that the notch in the front of the chassis is where the HDD activity LED is. With both lit currently, this may be the only way to tell if the system is running in the solid panel version, as with the fans that come with it, and what we put inside, we could not hear anything other than the post beep to tell us it was indeed on and running.

Final Thoughts

While this chassis sees a very new layout internally, the exterior offers all the things that have made Fractal Design and the Define series so popular. There is a lot of black on the outside, the front panel is closed off and redirects noise to the sides, and in our instance, we really liked the view the windowed version offers. Going with a drive bay-less design is something we have seen with many modular designed cases, it is few and far between that you find a chassis designed like this out of the box, where water cooling options take precedence over anything else, aside from noise suppression in a mid-tower design. There are the very expensive custom cases out there, but they cannot touch this chassis in a cost comparison. Even while stripping the front of what we would expect to see, and with so much digital media and most users opting away from optical bay devices, we have no issues with there being no 5.25" bays in this design. Also, while most other cases only offer six to eight bays for storage anyways, having five trays in the back of the motherboard tray will accommodate most users needs while staying hidden.

Also offering the brackets for a reservoir and mounting on the floor for the pump, it shows that Fractal Design is very forward thinking in this design, and was not so worried about what the chassis may lack from its predecessors, and in our opinion, this is a very good thing, as it drives them to come up with new things that many customers will find appealing for their next, hell, even their current builds. Even with the side panel window in our chassis, we also loved the limited noise during the testing phase. Of course, it could use more fans, as the flow isn't great, but the fact that the rear of the chassis is the only place we found noise, and limited to 31 dB at that, all of the additions to keep noises at bay work very well for this chassis.

That isn't to say that we found nothing wrong with this design, though. The panel was bent when we got it out of the box, but we feel that was just an oversight in assembly, and was easily fixed on a flat surface with a bit of pressure and effort; so not a deal killer. The one thing we did find while using this chassis is that the elimination of the bays on the front, while great for room and options, it definitely takes away from the structural integrity of the chassis. Where we have always said that Fractal Design cases are as strong as an ox, and have very little flex to the chassis with the panels off, this time around we cannot say the same thing. Once the heavier components are in the chassis, and you are moving it around for wiring and such, there is a very noticeable amount of flex to this design. Outside of those two things, we run out of complaints about the Define S.

The thing is though, even if it is a bit more flexible than the rest of the Fractal Design cases we have seen in the past, it is not excessive, or anything you don't see stripping down modular designs, so don't let it be a breaking point for you. With all of the inclusions such as sound absorbing materials, the ModuVent system, the internal layout, and all of that room found inside for water cooling, you will be very hard pressed to find a comparison at the pricing that Fractal released the Define S and Define S windowed version at.

Considering if you do not want the window, you can score this chassis for just $79.99 plus shipping, it is hard to deny the cost efficient deal there is to be had there. Even if you do opt for this version with the window to take advantage of the view of all the money you throw into the chassis, the additional $10 to the pricing and a few extra in shipping are well worth the extra cost in our opinion. Fractal Design broke the mold of what we should expect from them, and in our humble opinion, for this sort of pricing, it is super tough to pass up on this design for something else more expensive, and may not offer all of the goodies that this does, even if it can compete with the water cooling options, the Define S is just that nice of a chassis.

TweakTown award
Quality including Design and Build94%
General Features99%
Bundle and Packaging96%
Value for Money99%

The Bottom Line: Fractal Design breaks its mold for the Define S! This chassis, while smaller, packs in a ton of options both in cooling and sound absorbing, and both versions can be had for less than $100.

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Chad joined the TweakTown team in 2009 and has since reviewed 100s of new techy items. After a year of gaming, Chad caught the OC bug. With overclocking comes the need for better cooling, and Chad has had many air and water setups. With a few years of abusing computer parts, he decided to take his chances and try to get a review job. As an avid overclocker, Chad is always looking for the next leg up in RAM and coolers.

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