Top Mounting Radiators
By default, the Core X9 case can support a maximum of 4 x 120mm, 3 x 140 or 2 x 200 fans or a 480mm (4 x 120), 420mm (3 x 140), or 400mm (2 x 200) radiator mounted to its dual top-mounted brackets. The brackets are removable for easy installation and maintenance with slide-stype mounting holes to support almost any mounting configuration you could think of. The inside holes are for 120mm type mounting, the middle holes for 140mm mounting, and the outer holes for 200mm mounting. Note that a single bracket must be center mounted on top o the case to accommodate 200mm style fans or radiators.
Because of space constraints between the mounting brackets and the case top panel, the radiators or fans must be mounted to the bottom side of the brackets, facing the motherboard and floor of the case. The screws mount through the bracket and into the threaded holes in the radiator shroud or fan body.
Mounting slim-style 360mm radiator towards the front of one of the top brackets illustrates how the radiator would fit in the space. Mounting in this configuration requires removal of the top-most 5.25" device bay. In the configuration shown, the radiator inlet and outlet ports may require creative routing depending on what device is sitting in the middle or lower 5.25" device bay. Forty-five or ninety degree fittings may be required to route the tubing around 5.25" bay devices.
With the slim-style radiator mounted in the rear position of the top bracket, you open more space towards the top front of the case. However, the radiator inlet and outlet ports are very close in proximity a fan mounted in the rear position above the motherboard rear panel assembly. While the radiator does not impede on the space oft he upper 5.25" device bay, there may be space constraints between a device mounted in in the upper bay and a top-mounted 360mm radiator.
Even with a double thickness radiator installed in the top bracket, there remains plenty of room between the top-mounted radiator, motherboard, and vertically-oriented PCIe cards. In the rear-most mount position, the radiator can conflict with the rear fan mounted over the motherboard or the rubber-grommeted holes sitting over the motherboard's PCIe slots in the rear of the case. The radiator does not conflict space-wise with the top-most 5.25" device bay, but may impede on the ability to interact with cables plugging into a device mounted in the upper-most bay. Even with fans bottom-mounted to the radiator and mounted directly over the PCIe slots in the mothboard, there remains more than enough space between the radiator and PCIe cards for use and PCIe card-mounting / removal.
Mounting the radiator in the front position on the top bracket with the inlet / outlet ports in a rear facing orientation frees up space in the upper rear of the case. However, this type of orientation may introduce space concerns between the tubing coming off of the radiator and the motherboard or its PCIe cards. The radiator inlet and outlet ports sit directly over the motherboard, likely requiring use of angled barbs to avoid space conflicts with the motherboard or motherboard mounted PCIe cards.
The radiator's bottom section sits over the 5.25" device bays when mounted in the top front position, requiring removal of the upper bay to fit with fans mounted on the underside of the radiator. There should be no space issues in between the mid or lower 5.25" device bays and the radiator though.