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Cooler Master Master Box 5


Pros: Price, Very quiet operation, PSU cover, Windowed side panel

Cons: No top ventilation, Lacks additional features

Introduction and Unboxing

There are two types of computer builders: one who cares about performance above cost, and one who cares about cost above performance. Cooler Master's new MasterBox 5 is certainly aimed at that second category. It's a no-frills computer chassis meant to get the job done at a very affordable price point. The MasterBox line, launched as the little brother to the MasterCase line, is Cooler Master's step into the modular case market. Power supplies have become increasingly more modular over the past few years and I think this is a great trend for cases too. I have recently reviewed cases costing nearly 4 times as much as the MasterBox 5, so let's see what you really get for the price!

The shipping box did have a rather large hole in the top but the case was packed well so there was no damage. The accessories are pretty minimal; there's some documentation and a bag of parts. You get some single use zip ties, a Molex to fan adapter, standoffs (which were not pre-installed), and some case screws. It's just the bare minimum, but in the end it all works out.

Physical Tour

Here's the case itself. The back end is completely rectangular while the front narrows slightly inward. It's a relatively simple design and I like that. The left side is dominated by a clear plastic side panel. It's not tempered glass, but again that's not what I would expect at this price range. The rest of the case is standard matte black metal. The front panel is all smooth plastic which highlights the texture differences. The back panel is flat and has no bulge or fan mounts. For dimensions, the case measures 19.7" x 8.6" x 18.7" and weighs in at 16.3lbs.

The front features a full length dust filter which pops out easily to give you full access to the front of the case. There is space for up to two 140mm or three 120mm fans and two 5.25" drive bays at the top. If you want to use the 5.25" drive bays, you may have to purchase the cages separately and remove the dust filter. The top panel is interesting for its lack of any ventilation or fan mounts. Hot air naturally rises so this is the ideal place for fans blowing hot air out of your case, but all that air will have to go out the back. The front panel is pretty simple with a drive activity LED, two USB 3.0 inputs, an illuminated power button, headphone, microphone, and a reset switch.

With the front dust cover removed, we can see all the way through the case. The front fan mounts are adjustable and a standard 120mm fan is included. The back of the case also has another 120mm fan for exhausting air. They're nothing special in terms of performance. If you have high performance components that generate a lot of heat, I would highly recommend upgrading the fans to increase airflow inside the case. If you want to mount a triple radiator, you'll need an additional front bracket and you won't be able to use any of the 5.25" drive bays.

Opening up the case now we find a relatively simple all black interior. We'll start in the top left corner and move clockwise. First we see the CPU cutout behind the E-ATX compatible motherboard tray. It was plenty big enough for mounting coolers to the back without having to remove the motherboard. Next, behind the front panel, we have numerous SSD/accessory mounts. It's just a plate of metal with holes cut out for screws, but you can attach just about anything to it if you want. I think it may have been originally designed to also mount reservoirs or pumps, but I doubt anyone would seriously put a full custom loop in this case. The MasterBox 5 also comes with one pre-installed 2.5" drive mount. There are six large cutouts for cable management, but no rubber grommets to hide the cables themselves. I understand the three closest to the motherboard, but I don't get the other three. The front fans don't go there, the drive cages don't go there, so I'm unsure what they would be used for. If you are planning on liquid cooling, the only useful radiator mounting point is in the front (you can mount a single 120mm radiator at the back above the PCIe slots).

In order to accommodate a radiator in the front, the two included drive cages are movable. You can re-position them closer to the PSU in 3 steps. The SSD cage can be mounted behind the motherboard on the back panel, in the three vertical locations behind the front panel, or directly on top of the HDD cage. These features are part of the modular design of the MasterBox and MasterCase line. The MasterBox 5 is on the lower end so you can't do much in terms of customization, but it's definitely not as rigid as some traditional cases. In the bottom left corner we find the PSU cover which I'm really glad they included this as improves the look of the insides tremendously. It slides in and out and is secured with a thumbscrew from behind the case. It’s just a right angle piece of plastic so you can still see under it from the front, especially without the drive cages. Above that are 7 expansion slots. Most cases have 8 so a bottom graphics card likely won't be possible. The 7th slot has a mechanism to secure your peripherals at a LAN that Cooler Master is calling "StormGuard". It's a good idea but, anyone with a screwdriver who really wants your gear is still going to be able to take it.

Underneath the case there are two large feet with rubber padding on them. There is a dust filter at the back for the power supply, but unfortunately it is only removable from the rear.

With the drive cage removed, we can see the hard drive mounting system. There are two sliding trays included. Standard 3.5" HDDs can be installed easily without screws by snapping the four locking pins into the screw holes on the drive. Smaller 2.5" drives will require 4 standard screws. The drive trays slide into the cage and securely latch into place. Nothing fancy here, just a tried and tested design that works very well.

Moving around to the back of the case now, you'll find lots of openings and tie-down points. There's room for another SSD mount directly below the CPU cutout. The depth back here is pretty good and cable management shouldn't be a problem. I only wish they included rubber grommets of some sort instead of just big openings, but that probably wouldn't fit in the price point.

The Build

Now on to the full build. I was able to fit a 280mm radiator for the CPU and an additional 120mm radiator for the GPU all in this small case. The window looks great despite being plastic. It's tinted so things might get dark inside but some LED strips would look wonderful. Clearly visible from the front are the PSU cables however. Even though the cover hides them from the side, it's open towards the front so they are visible that way.

Checking out the back again you can see the cable management options. Everything fit well and I didn't have to do the dreaded "foot on the side panel" to close it. There is a nice trough at the bottom for routing and hiding the thick 24-pin cable as well as the front panel connectors.

I had a bit of trouble mounting that 120mm GPU radiator, but with some time and a bit of force everything fit well. I did my best to conceal the cables, but there's only so much you can do.


The MasterBox 5 from Cooler Master is a great little case. It's cheap and supports a wide array of components. It’s also pretty bare bones though, lacking many of the features of other cases. If you can do without the bells and whistles, this is a great entry level case. The clean aesthetic and large window make this case feel much more expensive then it is. Just a year or two ago a case with these features would have cost around $100. If you want more, you can check out the MasterCase line which is more modular and has some of those extra features. For under $70 at the time of publishing, it's hard to go wrong with this case though.

Here is a link to the forum post for discussion.


Pros: Fully modular/ Price

Cons: Dust cover slides from rear/ Only 120mm fan mounting out of box

You decide the inside. Cooler Master makes some of the most modular cases to date. They continues to innovate new ways to make computer building easier, and find numerous ways that allow the builder options. The MasterBox 5 is the newest addition to the MasterCase series. This case was designed to make building easier, and convenient for all system builders. Lets look at new ways to experience endless fun, and express your personality when building with the MasterBox 5.

The MasterBox 5 comes in two colors, White and Black. I will be testing the black version of this case.

The specifications are as follows:

Materials Steel body, Plastic mesh bezel Dimensions (LxWxH) 500 x 220 x 475mm Motherboard Support E-ATX, ATX, Micro-ATX, Mini-ITX Expansion Slots 7 Drive Bays Combo 3.5" / 2.5" 2 SSD 1 I/O Port USB 3.0 x 2, Audio in / out
Pre-installed Fan(s)
Rear 120mm x 1 Front 120mm x 1
Fan Support
120mm / 140mm x 2 *with optional bracket support up to 3 x 120mm Rear 120mm x 1
Liquid Cooling Support
Front 240mm / 280/ radiator, up to 50mm thickness without fan
120mm *with optional bracket support up to 360mm radiator
CPU Cooler 167mm / 6.5" PSU 180mm / 7.1" GPU 410mm / 16.2" (w/o 3.5" HDD cage) Cable Routing Behind Motherboard Tray 25mm - 35mm


The box was shipped in standard packaging. The case was well protected by Styrofoam, and a case sleeve. The sleeve helps reduce scratches and protects the window panel.

The accessories include:

MasterBox 5 manual/ Warranty info
  • Screw set (HDD/SSD/MB-mounting)
  • Zip ties
  • Molex fan connector
  • Locking bracket
  • Standoff Phillips head screw driver adapter

The Phillips head adapter for the motherboard standoffs was very useful for tightening down the standoffs to the cases frame. Sometimes when trying to remove your motherboard, the motherboard screws can start to unscrew the stand off which is really hard to undo.


The MasterBox 5 will unlock your computers inner potential. The cases design comes with conveniently placed cut-outs, making building easier than ever. The MasterBox 5 can support larger high-end components, air and DIY watercooling. Your system will look clean, and organized using the numerous routing holes provided. Create a design that follows your personality, and preferences.

The MasterBox 5 is fun and provides:
  • Ease of use and building
  • Flexible mounting options
  • Compact cooling
  • Good expansion
  • Simple modular design

The case provides maximum flexibility, and allows you to mount the parts where you want to, or not to.

The MasterBox 5 allows expansion support, and fits ,multiple motherboard sizes.

With flexible mounting zones you can easily mount and rearrange SSD, HDDs across the motherboard tray, along the bottom shelf or the back for SSDs.

The MasterBox 5 supports a large amount of room for cooling and building. It supports a CPU cooler of up to 167mm in height, and 410mm in length for GPU expansion.

The front of the case was well designed with metal mesh, and displays the Cooler Master logo.

The front panel connectors include:
  • HDD indicator LED
  • 2x USB 3.0 ports
  • Power button
  • Headphone and microphone 2.5mm jacks
  • Reset switch

Despite the many mounting options provided, there is no drive bays for DVD/CD installation. This isn't too critical as they are not very well utilized anymore. I did find plugging cables into the USB 3.0 ports were difficult to pull out, and not in a good way. The idea of the Master Box is a modular case design, so Cooler Master may be selling other accessories for this case, but nothing has been announced yet.

The bottom of the case provides an easy removable dust filter for the PSU. It is only removable from the rear which does provide complications if your system is against a wall. I hope to see the removable filters from the front in a future design. The feet are well-balanced, and extremely sturdy.

The two sides are built to easily slide on and off with ease. The side window is made of standard acrylic, but does display a large wide window for viewing your masterpiece. The back panel is really plain, but does provide enough room for cable management.

There is 35-25mm of cable space for hiding cables behind the motherboard tray. I would say the back of the case is plain, but does provide a blank canvas for custom artwork.

The cable management is also easily hidden by a PSU shroud, that can hide your PSU and the cables running behind the motherboard tray. I want to point out the small hole on top of the shroud. This is really useful for running your PSU cables to your GPU. I like to point out the small things like this that make a big difference for design.

The top of the case has no ventilation, but the front is where the design of this case takes the lead. The front does come with 1x 120mm Cooler Master fan. The case supports three 120mm fans, 2x on the front, and one on the rear. There is also a 120mm Cooler Master fan included for exhaust on the rear.

The front is where are the watercooling magic happens. You can install 280/240mm radiators on the front, and one 120mm in the rear.You can install a 360mm radiator with an optional front bracket.

The rear of the case supports 7x expansion slots, but there is something new I have never sen before, and this is where Cooler Master continues to innovate. They call it StormGuard. This cover slot is for security, and safeguards your peripherals.

I had no problem exposing the frame, or removing any of the HDD cages. Some cases make it difficult to remove the front or top panels. In fact you can remove the HDD cage with a single thumb screw. The front popped off by putting pressure on the 6 side tabs ( 3 on each side). As you can see from the picture they provide six routing holes for any system configuration.


Building inside the MasterBox 5 was extremely easy. The modular design and easy cable management makes this case really easy to work in.

The build used the following parts:
  • Motherboard- MSI Z97-Gaming 5
  • CPU: Intel Core I7 4790K
  • Network Card- netgear AC 1200 USB
  • Cooler- Silverstone Ar01 CPU cooler
  • Memory- Anarchy X 16GB DDR3 2800MHz
  • Video Card: PNY GTX 960 4GB
  • Storage- PNY CS2210 480GB
  • Power Supply- Cooler Master v700 series modular PSU
  • OS: Windows 10 x64 Pro
  • Headphones- HyperX Cloud II

My favorite part of building inside this case was the SSD mounting towards the top. Not only does it provide simple SSD mounting, it gives you options. You can easily hide your SSD behind the SSD mount, or proudly display your SSD logo. The best part is all you do is remove a single thumb screw. I can't say how much I love this, and it helps keep the computer looking great, and provides easier cable management. I only wish they added a second cage right below. Thank you Cooler Master for implementing this design. The other best part about building inside the MasterBox 5 is the PSU shroud. It provides extremely easy cable management, and hides your PSU well.


I am testing the MasterBox 5s acoustic performance with the included two fans from Cooler Master. The fans will be set to 100%, and tested with a high gain microphone. I will also include a video to display the audible noise of the system fans running at full speed. As you can see above the fans are right around the same acoustic level. I would say they are audible but not too distracting. The fans are easily controlled with a fan curve using your motherboards software, so you can adjust the audible level to your preference.

Cooler Master definitely has created a simple modular design that allows system builders to experiment with different options. This has been the most modular case I have worked with on the market.


This case does provide a ton of modular ability, but does have some negative aspects:
  • Only 120mm fan mounting out of the box
  • No top ventilation
  • Removing dust cover must come from rear
  • USB ports on front were hard to remove from

Despite only a few problems, this case truly shines in the cable management department. You get a PSU cover, and a ridiculous amount of cable access points. This has been one of the easiest cases I have worked with in a long time. It provides a nice clean look, while providing you with an amazing price. My favorite part of this build was the hidden SSD mount at the top, and watercooling options it provides for being a budget case. I was completely impressed with how great my build turned out, and all the options the MasterBox 5 provided me. I highly recommend this case for any one looking for lots of cable management features, and doesn't want to spend alot. You can buy the MasterBox 5 at MSRP of $69.99. The case will be available soon on Amazon, NewEgg, and at Micro Center.
Cooler Master Master Box 5

Fully modular case

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