Skip to: | | - A great place to buy computers, computer parts, electronics, software, accessories, and DVDs online. With great prices, fast shipping, and top-rated customer service - Newegg shopping upgraded ™

If you are reading this message, Please click this link to reload this page.(Do not use your browser's "Refresh" button). Please email us if you're running the latest version of your browser and you still see this message. - Computer Parts, Laptops, Electronics, HDTVs, Digital Cameras and More!

Cooler Master ATCS 840 RC-840-KKN1-GP Black Aluminum ATX Full Tower Computer Case

Sold and Shipped by Newegg

Purchases from these Sellers are generally covered under our Newegg Marketplace Guarantee.
Marketplace Seller
  • Aluminum ATX Full Tower
  • USB / Audio / IEEE 1394 / e-SATA Front Ports
  • 6 External 5.25" Drive Bays
  • 6 Internal 3.5" Drive Bays

  • Overview
  • Specifications
  • Warranty & Returns
  • Reviews

The bewildering range of computer cases available today is enough to confuse the most experienced tweaker. Every now and then, a solid, capable case with elegant design comes along that deserves more attention. Made of high-quality aluminum, the ATCS 840 provides optimum ventilation to your PC with a unique perforated screen design to maximize airflow. It's designed for easy assembly, cleaning, quick maintenance and upgrades.

The ATCS 840 can accommodate massive storage capacity, with six 5.25" drive bays, and seven 3.5" bays (including six hidden and one external) which provide for the installation of CD-ROMs and hard drives. Excellent cooling is provided by the 120mm rear fan, two 230mm top fans and the 230mm front fan, the PCI-Slot is equipped with meshed brackets for extra ventilation.

Easy USB, IEEE 1394, e-SATA and audio connectivity is provided on the concealable I/O panel. This is a great case for the do-it-yourselfer who needs a lot of flexibility!

  • newegg Aluminum Chassis With an all-aluminum construction, the Cooler Master ATCS 840 reaches the balance between chassis stiffness and heat dissipation.
  • newegg Superior Expandability with 13 Drive Bays Boasting six 5.25" external drive bays, and seven 3.5” drive bays (one external and six internal), the Cooler Master ATCS 840 provides expandability for future upgrade.
  • newegg Peerless Cooling Performance The Cooler Master ATCS 840 features one 120mm rear fan, two 230mm top fans and one 230mm front fan for exceptional cooling performance, as well as an air duct dedicated for graphics card cooling.
  • newegg Cable Management System The Cooler Master ATCS 840 features retaining holes for better cable routing and neatness.
  • newegg Pop-up Top I/O Panel With a simple finger push, the top I/O panel pops up for easy access to four USB 2.0 ports, one IEEE 1394 port, one eSATA port and two audio ports.

Learn more about the Cooler Master RC-840-KKN1-GP

Warranty, Returns, And Additional Information
  • Warranty
  • Limited Warranty period (parts): 1 year
  • Limited Warranty period (labor): 1 year
  • Read full details
  • Return Policies
    • Return for refund within: 30 days
    • Return for replacement within: 30 days
  • This item is covered by's Standard Return Policy.
Ownership: more than 1 year
Verified Owner
5/ 5
BRING IT BACK II 11/15/2013 1:25:39 PM

Pros: Greatest case ever made for normal people who like a big case, not a child's toy box! This was the single greatest case ever made with the best design feature of all, it looks like a computer, not a toy! It has great room, great functionality, and great air flow.

Cons: CM wasn't smart enough to update this great case with stuff like USB 3.0 and keep making MINOR upgrades to keep it current without making it cheap and plastic.

Overall Review: Update it, bring it back and make it the same way! Strong, sleek, and adult!

4 out of 4 people found this review helpful. Did you?
Ownership: more than 1 year
Verified Owner
5/ 5
Very popular case, so stop building it? 7/10/2013 12:13:59 PM

Pros: This is one of the best cases I have ever owned. There is more than enough room for anything made or will be made for a PC component.

Cons: Why the hell did they stop manufacturing this case? How many items do you see on Newegg with 5 stars that have 100+ ratings?
Cooler Master you seriously dropped the ball on this case. I need another one just like it.

Overall Review: Built my workstation computer and this case was so perfect for that purpose. I love Cooler Master cases but I don't want a gamer case for my workstation

2 out of 2 people found this review helpful. Did you?
Ownership: more than 1 year
Verified Owner
5/ 5
Bring Back ! Please !! 1/7/2013 10:43:42 AM

Pros: It's a can-do type PC case. Lots of room to acccess the MOBO, Video, Power Supply and above all the various Drive Bays. Drive Bay change outs are easy and simple. Wire management is easy with ample room to place the wires.

Love it that the Case is so Huge & heavy that when "loaded" your average jerk, ie lil Bro, Dad or da Sister, just isn't going to come and "borrow" your machine for a few.

Glad I got one in 2010 !!

Cons: Top fans would be nice to have a bracket to adjust the large top fans to accept the newer enclosed cooling systems that are on the market now. When I got the case in 2010 the Corsair H50 came out. Since then several types and variants have appeared. So just a bracket, please & thank you !

No star was taken off for this.

Overall Review: I've looked at lots of cases to up-grade or call it a chance to "modernize" but there isn't anything that can accept the huge Motherboards along with a really long Video Card. Oh sure, there are a few but you have to look long and hard and be very ready to back up to the pay window and empty out a lot of money $$ !! So Cooler Master amke it easier on everyone and BRING IT BACK !!

2 out of 2 people found this review helpful. Did you?
Ownership: more than 1 year
Verified Owner
5/ 5
BRING IT BACK!! 12/26/2011 5:10:53 PM

Pros: It was and still is the greatest case ever built! This is an overall opinion I give to this wonderful case! Some cases do better in one area or another, but NONE do all areas as good as this case does! They never should have pulled it from production, they should have just made minor improvements year after year to keep it on top! It's just sad to see it not in production. This case is perfect for the 1366, 2011 extended ATX boards and should be put back in production NOW!!

Cons: Cooler Master decided to stop building the greatest case ever in favor of building more plastic junk! I REFUSE to buy any case with as much plastic as the HAF or other cases CM makes. Shame on you CM for loosing your morals and shame on you for taking away this case!

Overall Review: I'm looking to buy one on-line or other places since I can't get it here! I won't build my next system till I find one at a reasonable price! CM should make a few design improvements and put it back into production, I would certainly buy it again and again until the form factors change to something that makes the case completely unusable!

1 out of 1 people found this review helpful. Did you?
Ownership: 1 day to 1 week
Verified Owner
5/ 5
Casing like a boss 4/25/2011 6:54:43 PM

Pros: Awesome sturdy brushed aluminum case/faceplate. Really well-built. This thing has so many smart features, its just absolutely built with us in mind, from the motherboard tray that slides out for an easy build to the built-in backplate cutout for an easy CPU cooling kit swap... It has none of the drawbacks my old mid-tower has.

I'm also very happy with the three 230mm fans they include, and the removable/washable dust filters (these should be REQUIRED in your next case purchase) that keep evil dust armies from foiling my world domination plans.

Cons: I can't fit a hot tub in it.

Overall Review: This case is better than you.

Did you find this review helpful?
Ownership: 1 month to 1 year
5/ 5
Awesome case 4/4/2011 10:27:03 AM

Pros: Very big case so lots of room to work with. Motherboard tray comes out which is hard to find these days. Also tolls design when it comes to dvd drivers etc..

Hard drives require 2 screws after you put them in their 3.5 holder. Which is very easy to do.

Cons: There are only two issues I can think of first is the front header panel sits hidden on top which pops up and allows you to insert 4 usb , esata, firewire devices as well as headphones, mic. It is to close to the power and reset button.

A lot of time I ended up restarting my computer by mistake due to this.

The second issue would be the fan filter for the power supply. it is on the inside next to where if you want you can add a 120mm fan on the bottom of the case. however to remove the filter to clean it for the PSU would require removing of the 120mm fan next to it.

Now the 120mm fan filter is on the outside of the case on the bottom. If they would have done this for the power supply filter it would have been perfect.

I have no idea what they were thinking.

Overall Review: I have this case for a year now and I have turn it into a media / file server. I really wish I found this case a long time ago. I replace a 10 year old metal case which was hard to work on.

The case is big and lack castors so I had to buy one of those computer caddy which works fine. It is too big and heavy to put on a table.

I would recommend this case in a hard bit. At this price range of $200 you can't get a better case for the money.

Did you find this review helpful?
Ownership: 1 week to 1 month
Verified Owner
5/ 5
Nothing short of FANTASTIC 4/4/2011 4:54:40 AM

Pros: This case is almost perfect, for starters the motherboard pins are taller than the average standoffs giving increased airflow under the Mobo also allowing for cables to run under for a neat clean build. The Mobo tray is removable and has brackets to reinforce it as so its not flemsey and slides out with ease.( A+++++) A tooless design on the 5.25 CD/DVD bays make installing DVD drives a breeze. I seen other reviewers complain about the drive bays being too tight and not allowing for the drive bay to be installed but I think they just didn't unlock the bay before attempting to instal the drive. I thought with 3 - 230mm fans it was gonna sound like a C-130 but its not, to my suprise its very slient. The 3.5 in hard drive bays are tooless also with rubber groments to eliminate vibration and noise.(excellent design) A++++ The massive size of this case allows for easy cable management with plenty of elbow room to work with and plenty of airflow to help keep the cpu nice n cool.

Cons: The only con I can think of (for me anyhow) is it didn't come with a window on the door but it can be ordered from cooler master direct for $30.00. I only wish it was taller so it could fit 8 - 3.5 hard drives. But as we all know.... those REALLY are NOT cons..... just a wish. I honestly can't think of 1 CON.

Overall Review: To continue the PRO's of this case ..... it also has an external 120mm fan that can be connected to the back of the Graphics cards to help aid in removing the heat from the GPU's . A+++ No sharp edges inside the case like in most of the cheap cases and a Beautiful brushed aluminum exterior. The case is watercooling ready for an easy cooling upgrade and also has plenty of room for those extra large cpu coolers. (ever buy an air cpu cooler and your case be too small?) This is a simple , well designed case, aimed at the enthusiast.

Did you find this review helpful?
Ownership: more than 1 year
Verified Owner
5/ 5
Best case I've ever owned. 3/17/2011 1:34:12 PM

Pros: This case is incredible:
- incredible for cable management
- slide out motherboard tray on ball bearings with a hole for installing CPU heatsink back plates.
- multiple mounting options for PSU (top or bottom)
- LOADS of space
- very nice and easy to use hard drive setup.
- sleek and clean design. Built for the "professional enthusiast".
- comes with every part you could ever need for setting up a computer (brackets, screws, etc.).

Cons: This case is HUGE, heavy and there's nothing to grab onto when you need to move it.
My computer doesn't need to move much luckily but I always need help when I go to move it.
Seriously, do NOT underestimate it's size. It's larger than any other full tower case I have owned in almost every way.

Overall Review: The sides are HUGE and I cut a custom window into mine that looks beautiful. Thanks to the full aluminum side panels it's a nice blank slate for any modders.

When I say HUGE I mean it. I was able to fit a full liquid cooling system inside the thing including 9 fans, TWO radiators (one 3x120 and one 2x120), the pump, a reservoir and all the tubing.

I have three graphics cards and an over-sized PSU as well.

Did you find this review helpful?
ICON Loading...
Selected Items
  • Add to Wish List
Are you an E-Blast Insider?
Subscribe Newegg e-Blast
Shop without retyping payment details. Secure shopping made faster.
Check out with PayPal.

Condition Guidelines

The following guidelines apply to all product categories unless otherwise indicated within specific categories.

  • New : This means the product will ship as received by the manufacturer, sealed, with all advertised components, and with the manufacturer warranty.
  • Refurbished : This means the product was tested and repaired as required to meet the standards of the refurbisher, which may or may not be the original manufacturer. Any exceptions to the condition of the item outside the manufacturer’s information should be provided in the listing, up to and including warranty details.
  • Open Box : Newegg only guarantees your receipt of the Open Box product with the purchase of this item. Any accessories MAY OR MAY NOT be included. Newegg will NOT send you any missing accessories, even if it is required to use all of the item’s functions.Open Box items usually do not come with manufacturer or vendor warranty or technical support. However, warranty support may be available if an item was never registered by a previous owner. Please contact the manufacturer to check.
  • Used - Like New : This means that the product has been opened, possibly used but is in perfect condition with no signs of cosmetic or functional defect. Product may includes warranty, and accessories found with the original product. Product may or may not be in the original packaging. Returned items with minor packaging defects fall under this category.
  • Used - Very Good : This means that the product has been opened, may show slight signs of use and cosmetic blemish, and may be missing minor accessories, but remain in excellent condition. Product does not come with warranty unless stated otherwise in product description.
  • Used - Good : This means that the product has been used, may show clear signs of use and may be missing minor accessories, but remain in good condition. Product does not come with warranty unless stated otherwise in product description.
  • Used - Acceptable : This means that the product shows clear signs of use, cosmetic defect, and may be missing minor accessories and manual, but remain in working condition. Product does not come with warranty unless stated otherwise in product description. Functionality issues beyond signs of use should be disclosed in product description.
Price Available at Checkout
Why can’t we show you details of this product?

Some manufacturers place restrictions on how details of their products may be communicated.

If the Adobe Reader does not appear when you click on a link for a PDF file, you can download Adobe Reader from the Adobe web site.