Noctua NH-D15 Orientation with one fan. I can't fit both fans like I'm sure most of you can't, so I tested two setups. The one you see now and rotated CW 90deg.
Noctua NH-D15 CPU Dual-Tower Heatsink Cooler Review
Noctua NH-D15 Review | RelaxedTech
Noctua NH-D15 chromax.black CPU Cooler Review - Appuals.com
Noctua NH-D15 Review (Page 3 of 4) | APH Networks
Reviewed: Noctua NH-D15S - PC Tech Reviews Australia
Noctua NH-D15S Review | Supreme CPU cooling with flexibility - GameRevolution