Installation and Performance

Before I could test the NH-L9x65 I did have to get it installed into our build. This would have been a little easier if I didn’t already have the build complete or if the case’s access opening in the motherboard tray didn’t cover the bottom two mounting holes. Anyhow I had to pull the motherboard out enough to install the backplate. This used to be more complicated but the design I all one piece and just slides right into the four Intel mounting holes. With that installed I reinstalled the motherboard. From there I had to put the plastic spacers on each of the backplates posts then installed the two adapter plates and screw down the bolts. From there I just needed to put our thermal paste on the CPU then remove the heatsinks fan and screw the heatsink to the now installed mounting plate. The springs on the mounting screws prevent you from having to worry about tightening things down too much or too little. Reinstalling the fan had me sliding the two clips into the screw holes and then sliding the clips down the side of the heatsink until they snap into place. All in all the installation was very easy with the hardest part being me trying to fit my fingers down below the heatsink to plug the fan in. If I installed the heatsink out of the tiny case it would have been a breeze.

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With my office temperature at a rock solid 70 degrees I then jumped into testing. I tested both the NH-L9i that I had installed in the case previously as well as the NH-L9x65 just for comparison, sadly given the specific application I wasn’t able to compare it to other large heatsinks. That said we can compare the numbers to the heat testing I did for this same Intel i7-6700K Skylake CPU with the larger Noctua NH-U12S that peaked out at 60 degrees Celsius on an open test bench. So for my testing I tested the 6700K on both heatsinks at idle and then with the CPU under full load using Prime95, both with the fan speed turned to 100% to prevent our motherboards fan profiles from effecting the numbers. At idle the numbers actually had me a little concerned. The L9x65 did run a little warmer but this is most likely because the NH-L9i’s thermal paste had been broken in a little bit. That said the full load numbers say it all. While the NH-9i was able to handle all of the other high wattage CPUs I have tossed at it when faced with the extra heat that the 6700K puts out it fell on its face running all the way up to a very concerning 91 degrees Celsius. The slightly larger NH-L9x65 however handled it much better with a peak temperature of 66 degrees Celsius. This is still a little warmer than I would prefer but given the small space, lack of case airflow, and the heat that the 6700K put out being only 6 degrees higher than a larger heatsink on an open test bench is very good.


To finish up my testing I did also do noise testing on both heatsinks. Given that they both had the same fan I wasn’t at all surprised that they both were basically within a fraction of a decibel on both idle and 100% fan speed tests.


In my testing I also got a few shots of each of the heatsinks in our Lunchbox 4 build. Here is the smaller NH-L9i. If you look closely you can see that the top of the fan actually ends at about the same height as the low profile ram.

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The larger NH-L9x65 might be over twice as tall but once installed it still looks small in our ITX case leaving a lot of room for airflow from the cases only fan to keep the rest of the PC cool.

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Then for those of you looking for a preview here is the build all together currently. But there are more changes to come before we rundown the entire build.

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garfi3ld's Avatar
garfi3ld replied the topic: #37871 01 Apr 2016 22:43
Today I check out the Noctua NH-L9x65, the big brother to the NH-L9i/a

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