Noctua NH-L9a-AM4 Review (Page 3 of 4)

Page 3 - Test Results

Our test configuration is as follows:

CPU: AMD Ryzen 7 3700X @ 3.6GHz
Motherboard: ASUS Prime X470-Pro
RAM: Ballistix Elite DDR4-4000 2x8GB DDR4
Graphics: MSI GeForce GTX 1070Ti Titanium
Chassis: Antec P120 Crystal
Storage: Western Digital Blue SN500 NVMe SSD 500GB, OCZ ARC 100 240GB, Patriot P200 512GB
Power: Seasonic FOCUS Plus 850 Gold 850W
Operating System: Microsoft Windows 10 Pro

Compared hardware:
- Noctua NH-L9a-AM4
- Noctua NH-U12S
- Noctua NH-U12A (Dual NF-A12x25)
- Noctua NH-U12A (Single NF-A12x25)

All tests were run in our custom-built computer to best reflect real life performance. The computer remained in the same location in the same room throughout all tests. The room temperature in our testing lab was around 25c. Stock thermal paste respective to all coolers were used to rate its performance; all pastes were given a proper amount of time for them to fully settle. The fans on all heatsinks were directly connected to the motherboard's 4-pin connector. Computer was turned on and idling for at least one hour for the idling tests. High CPU load results were obtained using the Prime95 in-place large FFTs test with a maximum number of worker threads for the tested CPU for a minimum of ten minutes or until the temperature was deemed stable. Temperature results were measured with HWiNFO, which reports the CPU's integrated digital thermal sensor for maximum accuracy. Each temperature result was calculated by taking the maximum value of the cores inside the CPU.

After letting my computer sit idle for a while, I shook my mouse to wake the computer to check the temperature. From the first graph, you can see the Noctua NH-L9a-AM4 was already idling at a higher temperature compared to the much larger NH-U12S and NH-U12A, with a result of 54c. This is not too surprising, considering how much smaller the NH-L9a-AM4 is compared to the much larger tower-style coolers. A total difference of six degrees over all of the cooling options is a notable result, but idle results do not give a full representation of what CPU coolers can do, so we opened up Prime95 and started the tests to see what would happen.

With a sufficient amount of time to load the processor, you can see how each of the coolers performed with the peak temperatures across all the cores and threads. Once again, the Noctua NH-L9a-AM4 struggled to cool the Ryzen 7 3700X with a very warm temperature of 83c. Once again, compared to the larger tower coolers, this was much hotter. Even though Noctua's website does state the Ryzen 7 3700X is physically compatible, it also notes this cooler will not be able to support overclocking or boost frequencies. As such, in addition to the higher temperatures, while all of the other coolers allowed for boost speeds of 3.8GHz across all cores, the CPU only maxed out at 3.7GHz with the NH-L9a-AM4 installed. Overall, the result may not necessarily be the most impressive, but this is more than understandable considering the overall dimensions and the purpose of the low-profile cooler.

As for the sound analysis section of the Noctua NH-L9a-AM4, on a scale of 0 to 10, where 0 is silence and 10 is the definition of loud, I would rate the NH-L9a-AM4 at 2.0/10 during idle and around 4.5/10 under full load for the single fan. Unsurprisingly, the NF-A9x14 HS-PWM fan is quite loud under full load, which makes sense due to the fan's small size and high rotational speed. On a day-to-day use, the fan is pretty quiet and spins without much noise.

Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Hardware; Installation
3. Test Results
4. Conclusion