Noctua NH-L12 Low Profile Heatsink Review
Author: Dennis Garcia
Published: Monday, March 26, 2012
Benchmarks
The Noctua NH-L12 is designed for Intel Socket LGA2011 / 1366 / 1156 / 1155 / 775 and Athlon 64 processors. Here is an overview of the system and testing methodology.
The system as it was tested
Asus Sabertooth P67 Intel Z68 Chipset
Intel Core i7 2600K (3.5Ghz) Quad Core 4 x 256KB L2 Cache 8MB L3 Cache
Noctua NH-L12
Cooler Master Hyper 212 w/ Noctua NF-F12
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.
Intel Core i7 2600K (3.5Ghz) Quad Core 4 x 256KB L2 Cache 8MB L3 Cache
Noctua NH-L12
Cooler Master Hyper 212 w/ Noctua NF-F12
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 7 task manager reported 100% processor usage we could never attain a 100% of the rated heat output as documented by Intel (see below) 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.
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.
Default Speed
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 = 95W
0.35 C/W = (49C - 21C)/(.85(95W))
C/W = (CPU temp - Ambient temp)/(Variance(%) * CPU Watts)
Allowed variance for this test = 85%
CPU Watts = 95W
0.35 C/W = (49C - 21C)/(.85(95W))
Overclocked
For this next test the CPU speed was cranked up to 4.4Ghz using the Asus TDP setting 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. The formula and constants for this are listed below.
ocC/W = dCPU Watts * (ocMhz / dMhz) * (ocVcore / dVcore)2
ocMhz = 4430
dMhz = 3500
ocVcore = 1.31
dVcore = 1.2
The variance still applies for our C/W calculation
Allowed variance for this test = 85%
CPU Watts = 143W
0.37 C/W = (66C - 21C)/(.85(143W))
ocC/W = dCPU Watts * (ocMhz / dMhz) * (ocVcore / dVcore)2
ocMhz = 4430
dMhz = 3500
ocVcore = 1.31
dVcore = 1.2
The variance still applies for our C/W calculation
Allowed variance for this test = 85%
CPU Watts = 143W
0.37 C/W = (66C - 21C)/(.85(143W))
Benchmark Conclusion
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)
Given that we used the new Sandy Bridge platform for these tests you will notice that the total heat output is considerably lower than any of our other heatsink tests. Yet, even with the lower 95w TDP we were still able to pump 143w of heat into the heatsink at 4.4Ghz and show it can handle a good overclock. In these tests you'll notice that the C/W numbers did change between the default and overclocked tests. All this indicates is that the heatsink was beginning to saturate and had some trouble dissipating the heat at the same rate.
It should also be noted that we did test this heatsink using both fans spinning under the Asus Turbo PWM fan profile. This profile is a little more aggressive than the default enabling them to spin up under load. Normally we would have cranked them up to get the maximum cooling possible but decided against that for this review. Despite the higher than expected OC load temps the NH-L12 ran extremely quiet and is really one of the primary reasons for using a Noctua cooler over an OEM design to begin with.
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.
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)
Given that we used the new Sandy Bridge platform for these tests you will notice that the total heat output is considerably lower than any of our other heatsink tests. Yet, even with the lower 95w TDP we were still able to pump 143w of heat into the heatsink at 4.4Ghz and show it can handle a good overclock. In these tests you'll notice that the C/W numbers did change between the default and overclocked tests. All this indicates is that the heatsink was beginning to saturate and had some trouble dissipating the heat at the same rate.
It should also be noted that we did test this heatsink using both fans spinning under the Asus Turbo PWM fan profile. This profile is a little more aggressive than the default enabling them to spin up under load. Normally we would have cranked them up to get the maximum cooling possible but decided against that for this review. Despite the higher than expected OC load temps the NH-L12 ran extremely quiet and is really one of the primary reasons for using a Noctua cooler over an OEM design to begin with.
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.
