The Noctua NH-D15S is a fantastic CPU cooler that improves on the already outstanding NH-D15. Overall, it usually stays within 1-2 °C of its sibling. With such fantastic performance on mainstream processors, the loss of a second fan does little to dampen its performance. It also doesn't hurt that noise levels are just as expected in that it's nearly silent. At 64 mm under the fins, memory clearance is good, and with the new asymmetrical design, expansion-slot clearance is greatly improved as well. Much like all Noctua coolers, the NH-D15S is easy to install thanks to the SecuFirm 2 mounting hardware, and let's face it, that paired with its exceptional build quality make this cooler a bit of a treat to work with. The fact that it's well packaged and has a nice accessories bundle is just icing on the cake. Oh and who can say no to an industry leading no fuss six year warranty?

The only negatives I can think of are a bit lacking. Noctua's NH-D15S packs a high price, and with a second NF-A15 fan, it hits nearly $110, which is quite a lot all things considered. Finally, there is the color scheme. We all know it's unavoidable unless one buys replacement fans. We also know it's part of it being a Noctua cooler, which still doesn't make it any easier on the eyes.

In my own opinion, the NH-D15S is the better cooler when compared to the NH-D15. The better expansion-slot clearance allows it to fit into far more builds, which gives it a wider appeal. That and the fact that users can still slap a second fan on for maximum performance without issue certainly doesn't hurt either. That second fan doesn't really matter on mainstream systems, but it would prove a bit more useful with AMD or Intel HEDT platforms. Noctua has definitely set a new bar in terms of what one can expect from monstrous heatsinks in that the NH-D15S is compatible with many mini-ITX and micro-ATX systems where the first expansion slot is PCIe x16.

If you want top-tier performance with ultra-low noise levels and extra expansion-slot room, the Noctua NH-D15S is a damn good option.