Unlike cheaper cases the Cooler Master ATCS 840 has a painted/polished silver interior. Plenty of cabling routes can be found for this case, especially since it supports E-ATX motherboards. CPU coolers are also easy to install and swap out with the large CPU cutout on the removable motherboard tray. The removable motherboard tray is removed by four screws on the back, but we will cover more on this later on in the review.
Yet another removable plastic filter covers the power supply fan grill for easy cleaning. The six 3.5″ drive bays face perpendicular from the 5.25″ bays and also have the connections facing towards the backside of the case leaving the clutter in the front to a minimum and also a quicker route to the motherboard. The easy to remove HDD racks will be explained later.
The 5.25″ drive bays have their own unique tool-free design. The device is pre-attached to each bay and once the drive is lined up with the front bezel just a simple push of a button will lock it in to place.
Along the back of the case you’ll find the seven expansion slots with VGA cooling vents to match it in addition to a 120mm fan found right next to the motherboard I/O slot.
A water cooling radiator can be installed along the two rails which extend from the 5.25″ drive bays to the rear of the case. This could however get in the way with an upper mounted power supply, which could also get in the way of the two 230mm fans found on the top of the case.