For testing the goal was to test all three coolers on our updated AM4 test bench which now tests using the Ryzen 9 3900X, Ryzen 5 3600X, and the Ryzen 5 3400G. The NH-L9i did cause a problem though considering it is the Intel model and at the time Noctua didn’t have their AMD version available. I’ve tested both of those in the past with our Ryzen ITX testing. You can check it out in the ITX Roundup and when I took a look at the AM4 L9a. The chromax.black version doesn’t change any of that, so I went ahead and left it out of our testing. But you can expect to see that cooler being used in an SFF build soon I’m sure!
Beyond that, for testing, I tested the U12S and the D15 on all three CPUs both with the stock fan profile from our Asus motherboard and again at 100% fan speed. I did those tests across three different types of CPU load as well. Our first round of tests was the most demanding of them all. The AIDA64 Stress Test using the FPU setting which is basically a worst-case scenario. Because Ryzen CPUs like to pull clock speed when they get warm I track both the temperature and the clock speed. The D15 I ran with a single fan and dual fan as well because I was curious how it would perform. No big surprise though when you see that with the dual fan configuration it ran the coolest and it was really the only cooler that kept the 3900X from throttling with the stock fan profile with one and two fans. The U12S ran warmer, no surprise there with its much smaller size. It did still outperform the Dark Rock Slim but the cheaper Hyper 212 did do better at 100% fan speed.
My next round of testing was still in AIDA64 using the stress test, but this time I ran the CPU setting which from my experience is a lot more like what you will see with high loads from normal programs and games. This is the only one I really worry about when it comes to SFF builds because it is the most realistic as well and as you can see I don’t need to track clock speeds for this one. Again the D15 just stomped everyone else, especially with the 3900X. Things even out more on the slower CPUs. I do like that even with just one fan the D15 is still a better option though. The U12S chromax.black stayed right with its normal counterpart for the most part which the Hyper 212 did still perform better.
The last cooling test is similar to the others but uses Blender to put the three CPUs under load. Blender is demanding so I do include the clock speeds again on this one. Not to sound like a broken record, but the D15, even in the single fan test, is just a monster. Keeping even the 3900X nice and cool. Here the U12S Chromax ran right with its original twin which was better than the Dark Rock Slim but again behind the Hyper 212.