Noctua NH-D15 G2 Chromax.black Heatsink Review

The Noctua NH-D15 G2 is designed for Intel Socket LGA1851 / 1700 / 1200 / 1156 / 1155 / 1150 and all modern AMD processors. Here is an overview of the system and testing methodology

Z790 Aorus Elite X WiFi 7 – Z790 Chipset
Intel Core i7 12700k (3.2Ghz) Sixteen Core 12+12 32KB L2 Cache 9+9 x 1.25MB L3 Cache 25MB 

Coolers
Noctua NH-D15 G2 chromax.black
Noctua NH-D15 G2
SilverStone IceMyst 420
SilverStone Argon V140

The CPUID System Monitor was used to obtain and record system temperature data and being that this is a quad core processor we need something that will work across all of the cores at once.  For this task we're using a new version of Prime95 (p95v255a) that will allow you to spawn (n) instances to test with.

Editors note: Even though the Windows 10 task manager reported 100% processor usage we could never attain a 100% of the rated heat output as documented by Intel when using Prime95 as a basis for that heat production. Knowing this we ran the stress test until the maximum temperature was attainted and stabilized.

Other things to consider when judging software induced heat output.

a) Clock throttling by the processor at high temperatures.
b) Normal software isn't designed to produce maximum heat output.
c) Variances of cooling temperature.
d) Variances in CPU load.
e) Inaccuracies in thermal diode readouts.
Of course the list goes on..

Our testing methodology is aimed to provide a real world look into this heatsink given the test system provided.

A C/W rating can quickly be calculated using this formula.

C/W = (CPU temp - Ambient temp)/(Variance(%) * CPU Watts)
Allowed variance for this test = 85%
CPU Watts = 125W (or 137W due to turbo clock)

0.33 C/W = (62C - 23C)/(.85(137W))

For this next test the CPU speed was cranked up to 5.1Ghz Sync across all cores and the test was re-run.

To calculate a new C/W rating for this test we will need to factor in the increased processor wattage.  However, given that the overclock is within the range of the max turbo frequency we will simply use the Max Turbo TDP

The variance still applies for our C/W calculation
Allowed variance for this test = 85%
ocC/W = dCPU Watts * (ocMhz / dMhz) * (ocVcore / dVcore)2
ocMhz = 5100
dMhz = 4300
ocVcore = 1.4
dVcore = 1.2
The variance still applies for our C/W calculation
Allowed variance for this test = 85%
CPU Watts = 278W

0.27 C/W = (86C - 23C)/(.85(278W))

In our heatsink and waterblock tests we don't really focus on overall load temperatures but rather how well the product can remove heat given a specified heat load. Since this is a real world testing method we need to take into consideration real world variables and estimate tolerances. This is why we normally only apply 85% of the total wattage output to our heat calculations.

The resulting C/W number is used to rate how efficient a heatsink or waterblock is based on the given heat load. These numbers can be used to determine heat capacity, the larger the difference the less efficient the heatsink is. (aka not good for overclocking)

There are a couple things to mention about these results.  First while the load temperature between the G2 HBC and G2 chromax.black are within a degree there was a rather significant difference in the ambient temperature.  The G2 HBC was captured at 26c while the G2 chromax.black was at 23c.  Normally this would translate into higher load temps for the G2 HBC however, the conforming cold plate specifically designed for LGA 1700 intel processors offers a much better thermal transfer and thus, lower load temps despite the higher ambient temp.

This difference also carried over to the overclocking tests where the G2 chromax.black posted a much higher load temperature but, with a lower overall C/W score indicating that this cooler has not reached its saturation point but does improve performance with higher fan speeds.

Keep in mind these calculations are provided for demonstration purposes only and may not reflect the actual lab tested C/W rating, but we're pretty close.