Rear Panel

The rear panel from ATCS 840 can be seen in Figure 8. By default the power supply should be installed on the lower compartment. This case, however, has a second power supply compartment on the top, which can be used if for some reason you want to install your power supply on the top or if you want to install two power supplies on this case.

In order to install a power supply on the top part of the case, however, you need to permanently remove one of the two top fans (or the two of them if your power supply is more than 8” – 20 cm – deep). Thus it is recommended that you install a power supply on the top only if you want a system with two power supplies. In this case you need to add a metallic holder for the top unit, which comes with the product.

ATCS 840, however, doesn’t come with the necessary adapter to make two power supplies to turn on at the same time. If you install two power supplies you will need to either buy this adapter or manually connect the green wire (pin 14) from the two power supplies together, to allow them to turn on at the same time when you press the standby (a.k.a. on/off) switch from the case.

Cooler Master ATCS 840 Case ReviewFigure 8: Rear panel.

This case comes with two holes protected with a rubber cover for installing external water cooling solutions, so you won’t need to drill or break anything on your case to install such solutions. These holes are available where the top power supply is installed, so if you install a second power supply you lose this feature.

There is a 120 mm fan on the rear of this case (you can monitor its speed if you install it directly on your motherboard).

This case has seven slots for expansion boards and all they use meshed covers, enhancing the airflow, especially if you use the feature we are going to talk next.

ATCS 840 comes with an external exhaustion chamber for the expansion boards. This is especially attractive if you have high-end video cards that generate a lot of hot air on the back of the computer, which probably is the case if you are willing to by this product. In order to use this device, however, you need to buy a 120 mm fan, because ATCS 840 doesn’t come with it.

Cooler Master ATCS 840 Case ReviewFigure 9: External exhaustion chamber.

Cooler Master ATCS 840 Case ReviewFigure 10: Chamber added to the rear panel.

As you can see this box has two holes protected by rubber covers to allow you to route the cables from your computer, like the monitor cable.

Now let’s take a look inside ATCS 840.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.