The box for the Noctua NA-HC4 chromax.white maintains the same aesthetic as other Noctua product boxes and displays the compatible heatsink model numbers on the front. Finally, a second box under the fan tray has the additional anti-vibration pads necessary for installation in every color. There are also four mounting screws if the fan is to be installed in a case. A low-noise adapter is also included. Now, let’s pull out this heatsink and take a look. I took this picture upside down, so let’s see the NH-D15S rightside-up. Yup. It is definitely asymmetric. A large 140mm Noctua NA-A15 PWM fan is clamped onto one side of the heatsink. An additional 120mm or 140mm fan can be installed on the other side but make sure it will fit in conjunction with your motherboard and RAM. One aspect of Noctua’s heatsinks has not changed: the NH-D15S like the –D15, the –C14S, the -D14 and others, all use the SecuFirm system. If you mount one heatsink, you can swap it for another Noctua heatsink in minutes. They make a reviewer’s job much easier. NH-D15S Pros

The comparator heatsink was the Noctua NH-D15. Each Heatsink was mounted with a 6 mm blob of NT-H1 TIM. Each time a heatsink was mounted, the TIM was allowed a day to fully spread before the temperature tests were run. The NH-D15S is at least as good as its predecessor, the NH-D15. It accomplishes Noctua’s main aims of making more room for a 1 st-slot card, bringing down the cost of the cooler, and making this heatsink truly compatible with tall RAM.Each test run was 60 minutes in duration. The last 50 minutes of each run was measured, and the temperature logs were analyzed in Open Office spreadsheets. An Intel chip reports its temps in one degree increments, so for best accuracy these reports should be averaged in aggregate. Here the core temps were measured once a second, resulting in 3000-line spreadsheets. The digital thermometer measuring air temp reported its measurements in increments of 0.1 °C. The ambient temperature was measured every five seconds, resulting in 600-line spreadsheets. The mean ambient temp was subtracted from the mean core temps, resulting in a net temp for each run. The net temps were then averaged. Upon removing the heatsink covers, you’ll notice a gray fixture on the underside of each cover. If you pull away in the corner, the fixture will come off as you break the connection of the magnets holding it in place. We utilized an Intel Core i7-10700K for this test and used the factory CPU settings of 3.8GHz at 100% load to put the cooler to the test. The second and third tests were performed with an OC stage of 4.7GHz and 5.0GHz, respectively. We wanted to see how well the Noctua NH-D15S performed in standard and high-end OC modes. However, even more impressive is our 79° temperature during 100% load! Just as with our idle temperatures, the D15S stayed in range of a high-quality 240mm liquid cooling unit, no pump noise necessary! Having forged their reputation on amazing performance, exceptional quality, and ultra-low noise levels, Noctua stands out as a premier manufacturer of PC-cooling products. Their can't-miss color scheme of tan and brown may not be to everyone's taste, but it does make them stand out. In fact, just about anyone who has ever built a PC can spot a Noctua product. That awareness paired with the knowledge that they offer some of the best warranty and after-sales support of any PC-cooling company has certainly garnered them a great deal of favor among enthusiasts. Well, that and their long-lived support.

The next picture shows you how you can fit a 140 mm fan (an NF-A15 in this case) as a push fan and still not interfere with your RAM – as long as you use low profile RAM. Those two threaded rods were for the tensioning screws. Noctua provides an L-shaped screwdriver for tightening the tension bolts. However, you would do well to get a 200mm long-shaft #2 Phillips screwdriver. Very helpful for this and for tightening motherboard screw deep in a case. You don’t need the extra features: If you don’t require the specific features offered by the NH-D15S, such as the asymmetrical design for RAM clearance, and you’re content with a more basic cooler, you can opt for a simpler and less expensive cooling solution. Final Remarks Noctua heatsinks have long been revered for their top-tier cooling abilities and quiet operation but their understated design and their brown fans specifically, are occasionally the subject of ridicule among PC builders who value aesthetics above all else. In essence, I tried to do all the things you might find logical to try. I used two different mounts to compare the cooling. I mounted the NH-D15S a third time with the fans blowing up – I had recently tested the NH-C14S heatsink and found a 5 degree difference in cooling, depending on how I mounted it. So I tried this vertical mount to see if it made a difference in how well the D15S cooled. The results are presented in different charts to keep the different mounts separate.

Upon removing the D15S heatsink from its box, I was amazed at its sheer bulk. This is a serious heatsink and it oozes quality. This is a heatsink you buy once and will re-use again every time you upgrade your system.

NH-D15S vs NH-D15.The first chart below appears to show that the NH-D15S cools 3 °C better than the NH-D15. Relax. What this chart shows is that when you mount heatsinks, your mounts can vary. In fact, you are well-advised to mount and test your cooling, then remount and retest. Stop only when you have arrived at a really good mount. Looking at our results, we see that three fans cool no better than two fans, with substantially more noise. Comparing the pair of 1200 rpm A15’s to a single 1500 rpm A15 shows that the pair of 1200 rpm A15’s cool this heatsink about the same as the single 1500 rpm A15 cools it, but more quietly (Not that the NF-A125 1500 was all that loud). Because Noctua provides only a single fan with this heatsink, if you have tall RAM you can use the money you saved and buy a 12cm fan. But really, there is no need for tall RAM in these days of 1.5v and 1.35v memory (even lower with DDR4). Buy low profile or ultra-low profile RAM. As usual, slower fans do not cool as well as faster fans, but they work more quietly. But here, running with two NF-A15 fans at 1200 rpm will be very quiet; and if you are willing to remount your heatsink until you get that “golden mount,” you can get very good cooling indeed. ConclusionsFinally, slide a cover over each fixture and the magnets do the rest. It’s that easy! You don’t have to detach the fan and can even do this while the heatsink is installed on the motherboard. Amazing!

If we installed a 2 nd fan, the D15S might even surpass an AIO. So, if you are after the highest possible performance and feel you must have an AIO to attain it, think again.The front of the box displays the fan’s specs as well as a small picture of the fan outfitted with the different colored anti-vibration pads. It also displays the included pad colors next to the fan. Inside, we find squishable foam – my favorite kind. The foam has some give to it and doesn’t break like Styrofoam. The foam surrounds fully recyclable boxes. But you are not going to recycle perfectly good boxes that were custom built for this heatsink and its accessories. The whole thing goes together too nicely. You will keep your box. Inside you’ll find the instructions, two white heatsink covers and two steel clips. Before I get into the installation, I must give kudos to Noctua for the excellent design of these covers. Not only do they look stunning but they way they are installed is ingenious! The stress tests were carried out with AIDA64 Extreme. We went with the Thermaltake View 71t instead of an open-bench setup. Three intake fans are located in the front of the Thermaltake View 71t, while one exhaust fan is located at the rear.