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Item#: 9SIA4CP2AN8830

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  • Overview
  • Specifications
  • Warranty & Returns
  • Reviews


Cosmos SE is the successor to Cooler Master's flagship Cosmos II ultra-tower computer case. It delivers the classic racecar look and feel of its predecessor in a smaller, mid tower package. Rails forged of aluminum provide sturdy handles for transporting your system. Although smaller compared to Cosmos II, SE still exhibits high-end features such as expansive support for all-in-one water cooling systems and hard drive storage. With the ability to install up to eight cooling fans or three radiators at once, Cosmos SE is capable of housing extremely powerful cooling components.

Iconic, Racecar-Inspired Design

Superior Water Cooling Support

Cosmos SE continues a lineage of classic design inspired by the supercars of today. Curved aluminum handles, sleek lines, and stylish blue LED accents provide a truly premium aesthetic.

Cosmos SE is capable of supporting up to three radiators at once, including a 120mm in the rear, 240/280mm on top, and a 360mm at the front. Cosmos SE allows you to pack massive cooling power in a perfectly sized enclosure.

Plentiful Storage Space for HDDs/SSDs

Large Cable Management Space

Uniquely designed combo trays can hold two SSDs each, providing support for up to 16 SSDs or eight HDDs in the hard drive cages. Two additional SSD mounting points are located on the backside of the main drive cage, allowing for a total of 18 SSDs.

A nice, clean setup is important for any high-end build. With Cosmos SE, you've got ample space to neatly store any loose cables with approximately 1.3-inch (34mm) of cable management space.

What's Included

Cosmos SE Computer Case

HDD Brackets

Accessory Pack

User Guide

Which Cooler Master Cosmos Computer Case is Right for You?

This Model

Cosmos SE

Cosmos II


ATX Tower

Ultra Tower

Motherboard Support

Up to ATX

Up to XL-ATX


10.4 x 22.4 x 20.6 inches

13.5 x 27.7 x 26.1 inches

Maximum Number of
SSDs Supported



Maximum Number of
HDDs Supported



Fan Support

Top: 120 / 140mm x 2

Front: 120mm x 2 or 140mm x 1

Rear: 120mm x 1

HDD: 120mm x 2

Top: 120mm x 3

140mm x 2

200mm x 1

Front: 120 / 140 / 200mm x 1

Rear: 140mm x 1

Side: 120mm x 2

Middle HDD: 120mm x 1

Bottom HDD: 120mm x 2

Radiator Support

Top: 240 / 280mm x 1

Rear: 120mm x 1

Front: 360mm x 1

Top: 240mm x 1

Bottom: 240mm x 1

Aluminum Carrying Handles

Removable Dust Filters

Learn more about the Cooler Master COS-5000-KWN1

Warranty, Returns, And Additional Information
  • Warranty
  • Limited Warranty period (parts): 1 year
  • Limited Warranty period (labor): 1 year
  • Read full details

Customer Reviews of the Cooler Master COS-5000-KWN1

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  • Kaleb L.
  • 4/28/2016 1:05:50 AM
  • Ownership: 1 month to 1 year
  • Verified Owner

3 out of 5 eggsDefective

Pros: This is an amazing case, tons of room great features, lots of cooling choices and configurations, love the case!

Cons: -It wasn't sold by newegg only on newegg
-It was defective and was missing the i/o connector to allow the use of the case power button...

Other Thoughts: Be careful when ordering on here that the item is actually a newegg item. Newegg is amazing at customer service and rma's, the secondary seller i purchased this through on newegg was not...

Did you find this review helpful? Yes No

  • 8/31/2015 7:38:06 AM
  • Ownership: 1 week to 1 month
  • Verified Owner

5 out of 5 eggsTotally Modular.

Pros: Modular EVERYTHING (see other thoughts). Ready for massive radiators and fans. Fits full ATX board and gear. Bottom-mounted PSU mandatory, excellent. Decent cable management, with lots of space behind the mobo tray. Toggle button for snazzy front lighting. Not bad for price.

Cons: A bit cramped at first. Side panel shape discourages lying on the side. It could do with a TINY bit more clearance inside, but it's already very large outside for a mid-size ATX case.

Other Thoughts: Gigantic video card (Zotax GeForce 970 GTX, 3-fan) didn't fit until I removed the middle drive bay wall. A couple screws out and POP, more room! Excellent air cooling gear, so I didn't use any liquid cooling (always room for that later on). A bit pricey for my taste, but not for the quality, and I'm a cheapskate.

1 out of 1 people found this review helpful. Did you? Yes No

  • Russell M.
  • 12/24/2014 1:42:57 PM
  • Ownership: 1 month to 1 year
  • Verified Owner

5 out of 5 eggsSuperb Case

Pros: Not sure why this case has only three eggs overall....everything about it is excellent. There is more than enough room for your components (even though I had to remove some HDD bays for my GPU, the process was easy), and the layout is slick and the cable management is a breeze. I even failed to put my liquid cooling bracket on before mounting my motherboard, but it was ok because the case had a spot in the back specifically so you could install/work on your liquid cooling without having to remove your mobo. The construction is mostly of high quality, and the case is beautiful looking. The buttons are all sound, and I'm not concerned about longevity in the slightest.

All my friends (quite a few computer builders) and family all really like the case as well.

Cons: There are no installed lights to show off your components through the glass. I bought a junky light, but it didn't light up the case much. While there are brighter options, there isn't really a good place to mount the bar-style lights in the case.

Other Thoughts: Don't be afraid of the reviews saying there is not enough room. I had more than enough to be comfortable with my ATX sized mobo. The case really is a cross between mid and full, but it feels like a full tower overall.

1 out of 1 people found this review helpful. Did you? Yes No

  • 12/22/2014 8:57:06 AM
  • Ownership: 1 week to 1 month

5 out of 5 eggsCOSMOS EZ...I MEAN SE

Pros: This awesome Mid-tower case follows the same "Super Car" body styling than that of its big brother; the Cosmos II. I've read many reviews stating the internal design makes the case crowded, and impedes on the overall airflow -- I beg to differ. I've found that with careful planning and a little patience, you can build a machine with high-end components without sacrificing airflow.

You can remove some of the HD cages to create ample space; because honestly, who is going to have more than 1-2 mechanical HDDs? I removed the bottom 2 cages, and still have room for 2 mechanical HDDs and 4 SSDs. (includes the 2 SSD mounts on the backside of the cage reservoir.) That leaves plenty of open space for air to travel from the front-mount fans, to the exhaust fans in the back.

Cons: I can see how having a front-mount rad might be a little annoying, but again...plan in advance and you'll find out the best set-up for your needs.

Other Thoughts: My build:

- CM Cosmos SE Chasis
- Intel Core i7-4790K Haswell Quad-Core 4.0GHz
- 2 x G.SKILL Ares Series 16GB (2 x 8GB) 240-Pin DDR3 SDRAM DDR3 1866 (total 32GB)
- 2 x SAMSUNG 850 Pro Series 128GB 3-D Vertical SSD
- 1 x Western Digital WD Green 2TB 64MB Cache HDD
- 1 x ASUS GTX 760 2GB 256-Bit GDDR5 GPU
- CORSAIR Hydro Series H100i
- CORSAIR AF120 Fans
- CORSAIR AX760 modular PSU

1 out of 1 people found this review helpful. Did you? Yes No

  • eric l.
  • 12/17/2014 10:19:23 PM
  • Ownership: 1 month to 1 year
  • Verified Owner

5 out of 5 eggsAwesome case

Pros: Everything about this case is great! It will hold a ton of hardware. I have a x79 saber tooth mobo, 4930k, 16 gb g-skill sniper 2400 MHz, sli 780ti sc gpus, 1000watt evga g1, 2-1tb wd blue hdd's, Samsung evo 120gb ssd and a corsair H110 280mm closed loop cooler in this case with room to spare.

Cons: None that I can think of.

Other Thoughts: More color options would be pretty awesome.

1 out of 1 people found this review helpful. Did you? Yes No

  • Adam M.
  • 12/17/2014 7:25:16 AM
  • Ownership: 1 month to 1 year
  • Verified Owner

3 out of 5 eggsits...ok....

Pros: i love the way this case looks. the handles make for easy movement. this case tries to do everything for every person. it has almost every feature you can think of but doesnt really excel any any one of them. with all of the front drive bays installed airflow would be greatly restricted. its a huge plus that you can remove them if not needed. it is nevertheless a great case for a good price and i would recommend it to others.

Cons: i would consider this more of an enthusiast mid-tower. as such, expect that people are installing a little wider than average motherboards. if you made the case an inch longer and gave more space for running cables through the grommets with full-width ATX boards it would be a huge improvement. my asus maximum VII is half covering the grommets on the left side of the board.

there are two issues with airflow in this case. one just plain stupid easy to solve and the other requires a bit more work:
1) if you install 2x120mm front fans the top fan is 1/3 blocked by the lowest 5.25" 'drive bay' which isnt actually a drive bay. this lowest 'drive bay' serves no purpose than to make it seem as if there are three front bays when there are only 2. no issues here with only having two. my issues is why do that at all. continue up the front fan grill and stop blocking 1/3 of a fan. it will look better and be more functional.
2) the construction of the front drive bays and the removable portions are far too restrictive to airflow. i have taken out all but the top portion of the front drive bays so i can improve airflow as much as possible. if i kept them in even with the jetflow 120's i replaced the included fans with i would have no airflow into the rest of the case. i have no doubt your design team can come up with something to give the same features without such a heavy cost to airflow.

Other Thoughts: nothing describes this case better than "jack of all trades. master of none." trying to include so much some things are compromised. however, i feel the changes i recommended above will have little impact to the overall purpose of the case while solving some of the most common complaints about it.

2 out of 2 people found this review helpful. Did you? Yes No

  • Aaron G.
  • 12/9/2014 7:44:44 PM
  • Ownership: 1 day to 1 week
  • Verified Owner

3 out of 5 eggsA few shortcomings...

Pros: I really like the look and feel of the case. I particularly like that it feels somewhat lightweight and the handles on top make it a bit easier to move around and the offsets on the bottom allow for a bit more airflow.

Cons: I read the reviews and had an idea of some of the troubles I may face ahead of time. I thought I may be able to overcome them and keep things a bit compact. One of my biggest issues at the moment is that, though it states it can support a 280mm radiator in the top position and that it will take up a portion of the top 5.25" drive bay, it fails to mention that the radiator can be no wider than about 145mm or it won't fit in that drive bay area. That could easily have been a non-issue if they had done as many other designs do and go for a tool-less drive install with sliders or just some inserts to attach drives there. It'd also give it a little more space up top, which it could use. I really needed all three drive bays, but could have gotten away with the radiator taking a portion of the top one, as what I was going to put there didn't use up all the space. This meant a front mount was also out of the picture, as it completely removes the ability to use the bottom drive bay. The front fans also seem to suffer due to the metal grating used as more or less a backplate with some holes in it to hold the fans. Which are then covered by big plastic pieces on the inside to hold the hard drives. On top of this, if both fans are installed (as it comes shipped) it blocks the bottom drive bay. Rather misleading to say it has three 5.25" bays when so many things will limit you to only being able to use two.

Other Thoughts: Overall, I wanted to like the case and make it work for what I needed. This couldn't be done. If I were building a more basic system it would probably have worked out. I may keep one of the two cases I got to use for a friend, but all I can say is I was really disappointed when this came in and some basic design choices made in unusable.

Did you find this review helpful? Yes No

3 out of 5 eggsBeauty flawed by bad design

Pros: The case is beautiful to look at and well made. There are no sharp edges and the steel and plastic match perfectly. The various panels remove and reattach with no problems. One look and you can see this is a class product and most definitely no cheap. Did I mention this is probably one of the best looking computer cases I’ve ever seen?

Cons: Before I start let me say I knew about all the cons before I bought the Cosmos 2. I looked at several YouTube videos and read many on line reviews. I definitely wasn’t lured into purchasing it. I had some ideas how to deal with the case’s shortcomings and it was too good a deal to pass up even though I had just bought a Corsair 230T to build this particular system in.
Honestly this case seems like it was designed 10 years ago when everybody was using spinning hard drives and big RAID arrays and you need a dozen hard drive bays. Don't they realize that today most people use 2 drives at the most and one of them is an SSD? It has 6 of the worst designed hard drive bays that anybody has ever seen. I don’t mean to say they don’t work well because they do but they’re bulky and block airflow from the 2 front fans and are needlessly complicated. There are twelve actual pieces to the drive bays and you need to remove six screws to pull them out. They’re not that hard to remove but then you find the front fans are connected to them and there’s no way to put them back without reinstalling them. You can reinstall 1 fan by using the included AIO brackets and that 1 fan will give you more air flow then using the 2 with the hard drive bracket.
Then they put 3 removable optical drive brackets on the front but only two 5.25 bays. The one is a dummy and actually blocks off part of the upper front fan. Did I mention the brackets are solid? You can leave it off but then the sleek looks are spoiled. Why not just put in the two 5.25 bays and 2 brackets and extend the perforated front panel up to cover the wasted space?
There is room for a 240mm AIL cooler on top but then you lose the nice 140mm fan that’s preinstalled there and you will also lose the top optical drive bay, leaving only one. You can install a 120 or 140mm AIO in the rear position and the 140mm fan will still fit in front. Push Pull coolers will work OK because there is room for one of the fans under the top cover.

Other Thoughts: I put a fairly robust system into the Cosmos 2 including an ASUS Z97-Pro, a Haswell i7 and an ASUS 760 video card. I have an SSD and a standard hard drive for storage and a Corsair H80i AIO cooler. I put the H8oi where the rear fan originally was and was still able to leave the 140mm fan in the top of the case in place. There are 2 sort of quick access 3.5 inch bays on the bottom that are accessible if you remove the front perforated panel and I installed the drives there. That allowed me to remove the restrictive drive bays in the middle. I’m going to build a frame to hold the 2 front fans utilizing the AIO brackets the Cooler Master supplies. The motherboard fits fine but is a tight fit and covers half of the rubber grommeted pass through holes. But everything fits and when you’re done you do have a beautiful if flawed case. Honestly, Corsair and other top tier case manufacturers have figured out how to make removable hard drive bays without blocking the front fans airflow and leaving the fans in place when you remove the bays. This is either arrogance or just plain poor design and it will probably ruin the experience for someone not willing to do a bit of modding. In a close one I’m going to give this case a thumbs down unless you’re running a 4 drive RAID array and then this is the case for you.

1 out of 1 people found this review helpful. Did you? Yes No

  • Kurt S.
  • 11/30/2014 2:21:36 AM
  • Ownership: more than 1 year
  • Verified Owner

2 out of 5 eggsTo cramped

Pros: Metal case and nice handles
can hide wires behind it

Cons: The front 2 fan intakes are just about useless as the way the case is setup the air cant go through as it gets blocked by the material the fans mount to.
The top intakes allows for a 240mm liquid cooling system however its a tight fit and with little room.
Its impossible to do a pushpull setup on a 240mm on the top without modifying your fans (cutting huge chunks of plastic off). Its possible its because I'm using a fullsize ATX board but like I said when I bought this the description page & section it was listed in advertised it as a FULL SIZE tower instead of mid tower. It just has a overall bad flow/design inside.
Can't purchase any parts for it like you can for almost all the other coolermaster cases. So if you break anything your doomed.
Not nearly as big as you would think specially because of how the layout is and stuff.

Other Thoughts: Skip this and buy either the newer model or something different entirely.

Manufacturer Response:

Good Afternoon Kurt,

I apologize your COSMOS SE is not working correctly for you as you have many different configuration with this case with minimal limitations such as radiator spacing to go beyond a push style radiator orientation on the top.

However, if you're in need of replacement parts we can assist you through our CM Store as well as a Support Ticket, Live Chat, and phones for the opportunity to assist you.

Please let me know for further questions.

Felinni M.
CMUSA Support

2 out of 2 people found this review helpful. Did you? Yes No

  • none .
  • 10/8/2014 7:52:14 AM
  • Ownership: 1 week to 1 month
  • Verified Owner

2 out of 5 eggsDisappointed

Pros: Great look(only reason I gave it two eggs) , have a cosmos 2 for my rig and thought this looked like the perfect fit for my latest build.

Cons: Michael H review for 5/15 sums it up perfectly , for this to be a flagship product from Cooler master I am really , really disappointed , should not be called a full . If your trying to fit a H100i into this thing with a Asus extreme board forget about it. Can't do without major modification 's and I mean major , losing one drive in bay area, dissembling half the drive bay area to do a front mount with the H110i I decided to take all components back out for another case, this one will sit for a smaller build , really bad design.

Manufacturer Response:

Good Afternoon Valued Customer,

I apologize your Cosmos SE is not working correctly for you as you have many configurations that you can build with this case including a front mounted radiator. Yes you will have to remove the front Drive bay cages in order to accommodate a front radiator as we published an official image with exactly this setup through our EU site and image linked below.

The COSMOS SE can only accommodate up to an ATX Form Factor to which an Asus Maximus Extreme Motherboard is an Extended ATX Form Factor with specifications of 12.0 inches x 10.7 inches (30.5 cm x 27.2 cm) compare to ATX specifications 12.0 inches × 9.6 inches (305 × 244 mm).

So yes, you will have to modify the case to fit this particular board, at this point I would suggest our COSMOS II.

If you have further questions or unsure how to setup a custom build such as this please contact us through Live Chat, Support Ticket, or Phone.

Felinni M.
CMUSA Support

Related File(s):
jpgCosmos SE Front Radiator

0 out of 1 people found this review helpful. Did you? Yes No

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Item#: 9SIA4CP2AN8830
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