The new Cooler Master ATCS 840 is an all-aluminum full-tower case supporting two power supplies, coming with four fans (one 230 mm fan on the front panel, two 230 mm fans on the top and one 120 mm fan on the rear), removable motherboard tray, several other features we will talk about and a very conservative looks. Let’s take an in-depth look at this latest release by Cooler Master.

ATCS 840 is available in two colors: black or silver. We reviewed the black version.

Cooler Master ATCS 840 Case ReviewFigure 1: Cooler Master ATCS 840.

Cooler Master ATCS 840 Case ReviewFigure 2: Cooler Master ATCS 840.

Don’t let the very conservative looks from ATCS 840 fool you: it has tons of features, being a very complete product.

In Figure 3, you can see its front panel. It has six 5.25” external bays, the lower one coming with a 3.5” adapter that can be used by either a floppy disk drive, a memory card reader or by a hard disk drive (the adapter has holes matching those on a hard drive, allowing this installation).

Cooler Master ATCS 840 Case ReviewFigure 3: Front panel.

On the front panel there is a projected aluminum plate and the space between this plate and the case servers as an air intake for the fan present behind the front panel. This fan is officially labeled as a 230 mm fan, but its blades measure 180 mm, making it to be smaller than other “smaller” fans. This is something we’ve been complaining a lot lately; we think the manufacturers should announce both the external size of the fan and the size of what really matters: the blades.

This plate can be removed to gain access to the washable dust filter present attached to the front fan.

Cooler Master ATCS 840 Case ReviewFigure 4: Washable dust filter for the front fan.

All fans from this case use a motherboard three-pin connector, allowing you to connect them directly to your motherboard and thus monitor their speed. They also come with adapters to install them directly to the power supply. No speed control feature is provided.


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.