A good server cooler is a rarity, because the main thing for the collectors of industrial PCs is a low price, and since the noise level in the servers is of little importance for anyone, it is easier to take a conventional extruded radiator with plate edges, put a fan on it at a speed of 10 thousand revolutions per minute - and will work.
However, if you are building a 3-4U high NAS on server components, or building a workstation or server that is installed in an open rack in the same room where the staff is working, you need a quiet, powerful, and most importantly - a compact cooler, and you are lucky if you can install a liquid cooling system in the case. And if not, then of all the options are only Noctua products. This well-known manufacturer of Hi-End coolers for enthusiasts creates a variety of cooling systems for Intel and AMD server processors. Each Noctua cooler is a work of art, and among the Noctua range there are small masterpieces for both 2U high servers and 3U-4U sized cases.
Model NH-D9DX i4 3U is interesting because it is compatible with Intel Xeon E5 processors with sockets LGA-2011 Square ILM and Narrow ILM, cooler does not overlap memory slots, so compatible with any DIMM modules. The air flow is created by a 92mm PWM-controlled fan and rubber pads that reduce vibration, and the radiator area is sufficient to remove heat from the average processor even if the fan on the cooler breaks down and only the front ones will work.
By default, NH-D9DX i4 3U has one fan with dimensions 92x92x25mm in the section between two arrays of edges. This installation on the one hand, eliminates any problems with clearance, when something rests for example in memory modules or VRM radiators, and on the other hand allows you to install fans - as many as three, if necessary. But the study of forums shows that even two fans for this cooler is already a luxury, and the maximum that can be achieved by this method is an extra 5-6 degrees, which is not important for the server processor.
Much more important is the noise level, which determines whether it is possible to install NH-D9DX i4 3U in a workstation for CAD/Video applications? As a rule, even OEMs in such configurations install liquid cooling systems, but often just say: accept it, it can not but make noise.
Here we have a minimum speed of rotation of the blades fixed at 400 RPM, and the fan can stop if the motherboard supports such a possibility. To protect against vibration installed rubber pads-ears, although 92-mm fan size is not as important as 120 and 140-mm caliber. In our test computer, the constant operation of the cooler was maintained at 600 RPM, and the cooling system was not audible against the background of the power supply. The claimed life time between failures (what is MTBF) is 150 thousand hours (17.1 years), and the warranty, determined by the reliability of the fan - 6 years.
The second important point is the cooling of the motherboard batteries by the cooler. Here it should be borne in mind that the NH-D9DX i4 3U can only be installed in one position relative to the socket, and on our motherboard its flow was directed towards the memory modules, although it would be more correct to deploy it to 90 degrees to cool the network 10-Gigabit chip and the radiator on the VRM. Of course, Noctua could provide such a possibility, making a more complex mount, but for the sake of universality used the mechanism SecuFirm 2, designed for server processors. The NH-D9DX i4 3U cooler can be installed on LGA2011, LGA2066, LGA1366 and LGA1366. I would like to note that for compatibility with the LGA1366 connector, the motherboard must have a backplate with thread. By the way, for compatibility with AMD processors with AM4 socket, the manufacturer has a set of mounts NM-AM4, which you can order on Ebay.
The base of the cooler is perfectly polished, which is not surprising - for Noctua this is the norm. Four heat-conducting tubes are bent by the letter U, and their tips are closed by caps.
Of course, the main advantage of this cooler is its height, which is only 110 mm, which allows you to collect quiet and compact workstations in HTPC-buildings and rack storage with a height of 3U.
Included with the cooler you will receive not only a syringe with thermal grease NT-H1, a set of mounting for Intel-ovskie sockets, but also a 4-pin step-down adapter Noctua NA-RC7, which is based on a 51 Ohm resistor. All motherboards for Socket 1366-2011 v4 have long been PWM-adjustable fan speed, so add an extra element in the power supply circuit of the cooler - a dubious prospect, it would be more useful to complete the cooler PWM-splitter Noctua NA-SYC1, especially since the installation of two fans is meant by the design of this cooler. Syringe thermal paste will be enough for 2 installation of the cooler, so it is better to save it, especially since it is one of the best thermal interfaces that you can buy for money today: it not only conducts heat well, but also does not dry over the years, so that the server heat sink can not worry.