Noctua Finally Did It | NH-D15 G2 Launching, Thermosiphon, & Fans

NH-D15 G2 Washer Mods, Coldplate Design

The $150 kit includes the cooler, the two fans, and four 1mm washers for an ILM mod. Noctua is at a point now where, as we’ve seen with air coolers in general, to further tune to get any additional performance it has to start doing tricks that may be outside of the cooler itself. The best coolers in our testing right now fall in a roughly 3-degree cluster, so fighting for an extra 1 or 2 degrees is very difficult at this point.

Where Noctua is trying to do that with the D15 G2 is going to be with three variations on the coldplate design. Those are called Low Base Convexity (LBC), standard, and High Base Convexity (HBC). The idea is to provide a better fit between the coldplate and the particular CPU it’s being paired with. For example, Intel’s current LGA1700 CPUs form a relatively deep concave shape when clamped down with the stock ILM, and an HBC coldplate may provide better contact and therefore better performance.

Back to the cooler itself, the D15 G2 has 8 sintered heatpipes (up from 6 on the original), and Noctua says it’s done some heatpipe tuning as well. Additionally, fin pitch and density has changed. You can see this below – the old D15 on the left and the new D15 G2 on the right.

The fans themselves are also different, which are a large contributor to the performance in any cooler.

We need to test it ourselves still, but Noctua showed first party test numbers against a fixed heat load. These scenarios suggest a roughly 3 degree advantage for the new G2.

Noctua PSU x Seasonic, Thermosiphon Cooler

Very quickly we’ll run through some other things at the booth.

There was a Noctua edition Seasonic power supply on display, but we don’t really cover those right now so we’ll move on.

There was also a prototype two-phase thermosiphon cooler that is pumpless (as in no moving mechanical pump) that cools by recirculating refrigerant through an evaporator in the coldplate and a condenser in the radiator. We’ve covered thermosiphon coolers in the past and the fact that Noctua is trying something like this is honestly super cool. Up until now we’ve only seen air cooling products from the company so this is something different. Noctua would like it to be comparable in performance to a CLC. However, Noctua doesn’t have this anywhere on its roadmap at the time of writing.

The company also showed off a few coolers designed for the enterprise and server market, like this one for NVIDIA Grace Hopper (GH200) chips.

Next-Gen 120mm Fan "NF-A12 G2"

More interesting for our core audience was the presence of a next generation 120mm fan, which looks like a scaled-down version of the NF-A14 G2. It’s technically unnamed, though one might say it could be called an NF-A12 G2.

Interview & Discussion

We also had another engineering discussion with Jakob Dellinger of Noctua. Go check out our video for the full thing – here’s a brief list of the major talking points from that discussion.

• Fan strength and material performance over time
• New load relief pad design
• Suggested fan screw torque of 2Nm
• Timelines for round frame and square frame versions of G2 fans
• Q1 2025 target for black version of G2 fans
• Noctua’s own thermal testing
• Coldplate curvature and style (Intel vs. AMD)
• Pressure scans