Optimal orientationOn Intel platforms, you can mount all the fans in whatever direction you desire, as long as your cooling system isn’t too big of course, or too close to the graphics card.
You’re generally advised to direct the flow of air towards the back of the casing rather than towards the top because most of the time the power supply is placed at the top and generally there's an extraction fan at the back. This isn’t a hard and fast rule however and on the highest end cases, the power supply is underneath and sometimes the extraction fan is automatically placed at the top of the casing, in which case directing the flow of air upwards isn’t a problem.
On AMD platforms, things are less flexible, with no choice in installation orientation, except with the NZXT. Thankfully, with the exception of the NH-U12P SE2, the flow of air is directed towards the back of the casing. Noctua supplies a free mounting kit
on request to change the direction of the flow.
As the Noctua NH-C14 and the Scythe Susanoo aren’t tower coolers, their flow of air is oriented directly towards the motherboard. The advantage of this is that the processor power stage, the memory and, for the Susanoo, even the graphics card are cooled at the same time. However, this isn't essential as both the processor power stage and the memory have in any case been designed to function without a fan.
Cooler orientation and memory
It’s important to note that the orientation of the cooler can have an impact on whether or not you can use memory modules accompanied by large radiators. The fan may fit above standard memory, which we measured at between 30 to 35 mm from the socket depending on the model, while with some radiators the memory can extend to as much as 50 mm.
Looking at the distance that separates the centre of the cooler from the extremity of the fan, on our Intel DP67BG test motherboard, when this distance is beyond around 51 mm the fan extends above the first DIMM and when beyond 60 mm it extends above the first two DIMMs. On an AM3 motherboard such as the M4A889GTD PRO/USB3, you gain an extra 1mm which can sometimes make all the difference
The most problematic example is the Silver Arrow, as with two fans it's above the first four DIMMs at the same time as only leaving 30 mm in vertical space, which means your only choice is to use memory bars with fairly simple heatsinks. The G.Skill Ripjaws for example, require around 40 mm of space and the Corsair Vengeance 50 mm.