Best CPU Air Cooler Under 155mm

[LutaWicasa]

As the title states.
Building a rig for my son....that's the size limitation with the case that'll be used.
Cooling an i7 6700K on an Asrock Z170 Extreme6

Haven't a clue if he'll oc it...but if so, it'd most likely be modest.

 

[ATMINSIDE]

Check the one in my mITX build, signature has it and I'm mobile, but it holds 4.5GHz on my 6700K without issue.

 

[LutaWicasa]

Okay....why the U9S ver over the D9L?

 

[ATMINSIDE]

The U9S, IIRC, has more surface area.

 

[LutaWicasa]

The U9S, IIRC, has more surface area.

But....this taken from the review on the front page:
The NH-U9S has more heatpipes than the NH-D9L, and taller heatsinks as well. But it doesn’t quite match the tandem tower in its cooling prowess. Still, it pulls air though quietly.

 

[ATMINSIDE]

With stock fans they look to be within 2°C of each other, go for either you like