Optimal orientationOn an Intel platform, it’s up to the user to choose the orientation of the fan. 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, except in casings where it’s underneath. There is however generally an extractor fan at the back.
On the AMD platform you have no choice. If you use motherboard mounting brackets, the flow of air will generally be directed towards the top of the casing where the power supply is generally positioned. In higher end casings the power supply is placed at the bottom and there’s also an extractor fan at the top.
Directing the flow of air towards the power supply isn’t a great idea as this heats it up a bit, though it isn’t a disastrous solution. Three of the coolers are an exception to this rule and direct the air towards the back of the casing on AM3, using standard mounting brackets: the Cooler Master Hyper TX3, Scythe Katana III and Zalman CNPS 5X.
Other coolers require you to uninstall the standard AMD brackets on the motherboard and use proprietary ones instead, in which case you can sometimes orientate the airflow towards the back of the casing. This is what happens with the Cooler Master Hyper 212 Plus and the Xigmatek Gaia SD1283 and Loki SD963. In spite of the fact that it has a proprietary mounting bracket, the Noctua NH-U9B still directs the flow of air towards the top of the casing.
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 can 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 50mm.
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 51mm the fan passes above the first DIMM and when beyond 59mm it passes 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.
Not many coolers go beyond this limit however: the Arctic Cooling Freezer 7 Pro Rev.2, the Noctua NH-U9B and the Scythe Big Shuriken all do. In this case, the simplest thing is of course to use standard memory modules, but when the cooler is mounted with the flow of air towards the top of the casing, it is possible to use the second DIMM with a bigger memory module on the Arctics and Noctuas, something worth taking into account on purchase!