X-bit labs

Two Towers: Noctua Heatpipe Coolers Review (page 3)

Category: Coolers

by Sergey Lepilov

[ 04/17/2006 | 04:09 PM ]

Noctua NH-U9 and NH-U12: Closer Look

The coolers represent the already classical “tower” design: a copper foundation with heat pipes going through, and aluminum plates on the pipes.

What’s externally different between these two coolers is their size. The number of aluminum plates and heat pipes, and the base area are absolutely the same, so I am going to describe the senior, NH-U12 model in detail, mentioning special features of the junior NH-U9 where necessary.

So, we’ve got 38 aluminum plates here and the dissipation area of the NH-U12 is over 5000sq.cm (as opposed to the NH-U9’s 3800sq.cm).

The aluminum plates are the same thickness of 0.4-0.5mm in both the models. The senior model is 29mm taller, so the plates are placed at a different distance: about 2mm in the NH-U9 and about 3mm in the NH-U12. It may mean that a faster fan may be necessary for the Noctua NH-09 whereas the NH-U12 can get along well enough with a low-speed fan. By the way, Noctua puts an emphasis on that issue in its press release about the reviewed coolers, saying that both the heatsink models are highly efficient even with a low-speed fan. We’ll of course check this claim in our tests shortly.

The ends of the heat pipes are neatly soldered up at the top. A few slits and holes of unclear purpose can be seen nearby. I suppose they were used when the heatsink was being manufactured or assembled.

You can see in this snapshot that the edges of the aluminum plates are profiled, just as I’ve seen in coolers from other manufacturers. This profiling is meant to minimize resistance to the air flow and to increase the overall cooling efficiency. The copper heat pipes are offset a little relative to one another – I think it is not because the heatsink design demands so, but because the manufacturer wanted to distribute the thermal load uniformly in the heatsink’s plates.

Note also that the middle part of the heatsink’s side plates is curved in to narrow the air flow and drive it along the plates rather than sideways. The engineers have really paid attention to every small detail and reduced airflow loss to the minimum in this design.