Cooler Master Cosmos C700M

The Cooler Master Cosmos C700M Case is Still One of The Best Around

I have built a lot of PCs over the past few years and they pretty much all have the same thing in common. You slap the motherboard into the frame the same way, wire some components together and try your hardest to keep things as clean and tidy as possible. While building a PC can vary from case to case, I have never experienced a PC case as versatile and if anything, overwhelming as the Cooler Master C700M. There were times when I absolutely hated it, it cut my hands, refused to click together and my back ached for days on end as I carted the damn thing around the studio while trying to get it set up. However, in the end, the experience was insightful and I don’t regret a moment I spent on it.

Watch this case in action below

The Cooler Master Cosmos C700M is definitely not for the faint-hearted. This case comes with levels of customization and freedom that you won’t find anywhere else. You also need to keep in mind that this case was released back in 2018 and even a few years later, it still holds up as one of the best around. Sure, some of the parts, in this case, are a bit dated. For starters, it packs a lot of old-school drive slots that you’ll probably never use. The same goes for the SSD slots that are also now replaced with internal M.2 slots on your motherboard. Thankfully, for every slot you don’t use on this Cosmos case, it means having more space to install other stuff and an open area to experiment with moving things around.

Out of the box, the Cooler Master Cosmos C700M already comes set up for your traditional PC case layout. This beastly case sits 650mm tall, is 306mm thick and can weigh anything between 25Kgs and 30Kgs depending on how much metal you remove to get to the PC layout you want to use.

Cooler Master Cosmos C700M

In the box, you’ll find the PC case sealed up and ready to go. There are also some additional vents and accessories that again, are completely optional. Once you’ve opened up the PC and removed it from the box, Cooler Master has also packed in the riser card and toolbox into the PC case for easy access.

MORE –Gigabyte X670E AORUS Master Motherboard Review

The case has two giant sides that open and close. One side is a gorgeous curved glass frame and the other a sleek metal shell. These doors can easily be removed and I recommend doing so when building your case. The front and top panels are also both removable. This makes it easier to get into the case when building. In fact, everything you remove on this case doesn’t have to be put back which is really the fun of the experience here. Even the back panel can be replaced with a completely different grate.

Cooler Master Cosmos C700M

The case also includes some ports and I/O which include the following:

Model Number



Grey, Silver, and Black



Materials – Side Panel

Curved Tempered Glass, Steel

Dimensions (L x W x H)

650 x 306 x 651mm / 25.6 x 12.0 x 25.6 inch

Motherboard Support

Mini ITX, Micro ATX, ATX, E-ATX

Expansion Slots


5.25″ Drive Bays


2.5″ / 3.5″ Drive Bays (Combo)

4+1 (In The Accessory Box)

Drive Bays – SSD


I/O Port – USB Ports / USB 3.1 Type-C


I/O Port – USB Ports / USB 3.0 Type-A


I/O Port – Audio – 3.5mm Headset Jack (Audio+Mic)


I/O Port – Audio – 3.5mm Mic Jack


I/O Port – Fans / Lighting

Fan Speed Control Button, ARGB Control Button

Pre-installed Fans – Front

3x 140mm PWM Fan (Speed: 1200RPM / Connector: 4Pin)

Pre-installed Fans – Rear

1x 140mm PWM Fan (Speed: 1200RPM / Connector: 4Pin)

Fan Support – Top

3x 120/140mm

Fan Support – Front

3x 120/140mm

Fan Support – Rear

1x 120/140mm

Fan Support – Bottom

2x 120/140mm (Bracket Needed)

Radiator Support – Top

120mm, 140mm, 240mm, 280mm, 360mm & 420mm (remove ODD, maximum thickness clearance 70mm)

Radiator Support – Front

120mm, 140mm, 240mm, 280mm, 360mm, 420mm (requires removal of ODD cage)

Radiator Support – Rear

120mm, 140mm

Radiator Support – Bottom

120mm, 140mm, 240mm

Clearance – CPU Cooler


Clearance – GFX

490mm (w/o 3.5″ HDD BRK), 320mm (w/ 3.5″ HDD BRK)




Full Tower

I was a bit ambitious with my approach to this Cooler Master Cosmos C700M build. Instead of making use of the layout that was already on the case out of the box, I decided to completely remove everything from the case and start from scratch with the attempt to build what is called a chimney layout.

Cooler Master Cosmos C700M

This chimney layout would see the motherboard sit in the middle of the PC with the I/O ports facing downwards and the GPU attached to the side of the case with the cool verticle mount included in this case. Of course, getting there was easier said than done because this case wants you to know that the laws of physics still apply to PC building and you can’t just install stuff anywhere and hope it all works.

The Cooler Master Cosmos C700M includes a large mounting bracket that is the most important piece of metal to keep in mind when installing your motherboard onto the case. This strip screws into either the left or right-hand side and you have to count ten screw holes in order to get the positioning just right.

Cooler Master Cosmos C700M

As for the motherboard mount. It is also pretty cool. The mount can be installed externally onto your motherboard and then thanks to the rubber connectors, it slots into this bracket without the need for screws. This meant I could also move the mount up and down if I needed more space for more components, which I did.

The motherboard bracket also acts as an external test bench so you can technically build the entire PC on the outside of this case for benchmarking and move it into the case when you’re ready to go.

Cooler Master Cosmos C700M

It took a few tries to get it right but after a while, I finally had the motherboard mount installed correctly. I also originally used the verticle GPU mount to place the GPU next to the motherboard. However, I completely overlooked the fact that I would need space for the HDMI and DisplayPort cable underneath it so I ended up moving that too.

Somehow, and I don’t think the case is meant to do this, I installed the GPU against the front-facing fans using the mount. I think the result ended up looking pretty cool and ventilation should be even better thanks to the Gigabyte Aorus RX6750XT’s thermal chamber that sits just above the fans.

Cooler Master Cosmos C700M

Cooler Master also sent me the MasterLiquid M360R cooler which was one of the easiest coolers to install. I installed it on my new Gigabyte Aorus X670E motherboard and attached the fans to the radiator. I also originally wanted to mount the cooler to the bottom of the case but after sitting through forums of people telling me it would shorten the lifespan of the component, I decided to switch it to the top of the case. This also meant I had to move everything down slightly but that wasn’t a major problem because again, the motherboard bracket’s rubber connectors simply unplugged from the upper slots and plugged into the lower ones.

Cooler Master Cosmos C700M

The MasterLiquid M360R comes with its own control box which at first, I decided to not use. The Cosmos Case also has a box so I routed all the fans and ARGB through that box instead but it didn’t end up working as expected. I will explain why in a bit.

After installing all the components, I then had to plug them all in. Cooler Master sent me the M2000 Platinum Powersupply which is a whopping 2000W PSU. Did I need this much power? Surely not but I won’t complain when I finally have a 40-series GPU in this PC… one day, of course. The PSU is modular and the Cosmos case also enables the ability to install the power supply box on either the top or bottom. You can also try other positions if you’re adventurous.

Cooler Master Cosmos C700M

The sheer freedom on offer when it comes to where the components are positioned in this case means the wiring is also no longer restricted to where they run. You can stick adapters through every small hole and even unclip the motherboard bracket, wire things around the mount and plug it back in. I am not joking when I say there is no limit to how you install things in this case. I also enjoyed how open everything was. The fact that the grates and panels slide in and out, made wiring and plugging things in so much easier.

I could also just cover up a nasty wire mess with a hard drive bracket if need be. Again, these parts are just modular so you can fit and tuck them into almost anywhere. An example was the GPU. I ran the HDMI cable through the bottom of the case so I simply installed the black panel, wired everything including the power supply and slid the grate over the top to hide everything away. If this was another case, I would have to either squeeze my giant hands into small holes or completely dismantle the faces to get into the tight areas.

Cooler Master Cosmos C700M

Of course, I did have a few issues with the case but it was more troubleshooting than anything else. For example, if I wanted to use the cool RGB lights on the cooler and MasterLiquid fans, I had to install the control box for that equipment. I was hoping the Cosmos box would offer the customization but it doesn’t speak to Cooler Master’s Master Plus software as well as I hoped. So in the end, I linked the cooler to the provided control box and the case to the installed box and it all worked. I did have one strip of RGB that refused to change colour when synced to the software but it was still better than nothing.

Cooler Master Cosmos C700M

I think the biggest takeaway from my time with this case is how enjoyable the troubleshooting issues were and how fantastic the experience is when you’re given something with this much freedom. This case is overwhelming. I am not going to pretend it is not. However, the best thing I could do for myself was to remove every single mount and cover and find ways to put it all back together. The process behind this all taught me new ways to approach PC building that break away from the traditional layouts you find out there.

Cooler Master Cosmos C700M

I would never have had the same experience with another case. So yes, this case isn’t perfect and sometimes I felt like just throwing in the towel, especially when I was tripping over wires, grates and components. But I loved the experience that went beyond just following the same old building process. In the end, my motherboard faced upwards, my GPU is beautifully displayed in an upright position and all the wires are neatly fed through the back grate which is also unlike your traditional PC case.

Thanks to Cooler Master for sending this through for me to play with. You can find out more about the products featured in the content below:

Marco is the owner and founder of GLITCHED. South Africa’s largest gaming and pop culture website. GLITCHED quickly established itself with tech and gaming enthusiasts with on-point opinions, quick coverage of breaking events and unbiased reviews across its website, social platforms, and YouTube channel.

1 Comment

  • John Kennedy 1 November 2022

    Shame you can’t buy it no more.

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