Overall and Final Verdict
So how did the two heatsinks do in our testing? Well noise testing, as expected both performed really well compared to everything else. I was hoping the new fan with the NH-L12S would be a touch quieter when testing at 100% fan speed but its hard to really be disappointed when they are both quieter than almost everything else.
So the NH-L9a-AM4 was what I was most curious about going in. They changed the design and are now offering an AM4 specific design in addition to the normal AMD model. It has a wider heatsink so I was curious to see if that would mean better cooling performance. In the end, it translated to about 1 degree better. Now considering that none of the other coolers are this thin, gaining any cooling performance is awesome. I would be curious to see if it would perform better with the NF-A12x15 PWM mounted on top to actually cool some of that extra heatsink that was sticking out. Getting the NH-L9a-AM4 installed isn’t as easy as with other Noctua coolers. About equal to the average cooler from other brands, but the mounting design does allow for the 37mm design to be possible.
As for the NH-L12S, well for starters it is a huge improvement over the older NH-L12, especially if you don’t have room for a fan on top. At 70mm thick it is thinner than the two main AMD coolers as well as the Phanteks PH-TC12LS and it outperforms the Phanteks and Wraith Spire. Its actually one of the best of the coolers tested overall. You also have the option to add a second fan later if you want for a push/pull configuration for a little extra cooling performance. Its installation is much easier because you get the standard Noctua mounting solution. That also means you will see new brackets in the future with new sockets if they are needed so it could outlive your next few PCs. The only downside to the design really is with the ram clearance. There is only one mounting option where you get any more than basic clearance, but I wouldn’t attempt anything very tall as it's not going to fit.
So what about pricing? Well, the NH-L9a-AM4 has an MSRP of $39.90 and the NH-L12S has an MSRP of $49.90. Noctua coolers aren’t exactly known for being the cheapest, but you do get a full tube of thermal paste. Thin cooling fans, especially fans that are this quiet are hard to come by as well and that is taking up a portion of the cost. The NF-A12x15 PWM would cost you $20 to pick up independently and it is $16 for the NF-A9x14. That is nearly half the price. Overall though, the prices aren’t bad for what you get. With the NH-L9a-AM4 there are almost no other options this thin in the first place, so just being able to find a heatsink this thin that can run high-end CPUs at all is great. Then with the NH-L12S, well it ends up being a great performer in that sub 80mm range. With both of them it is very dependent on the space you have in your SFF build. I wouldn’t run the NH-L9a-AM4 if I could fit one of the better performing taller coolers or the NH-L12S if I could get a larger heatsink or an AIO in. But in their specific size requirements, both have great performance in both cooling and noise. Now the tan and brown colors, I’ve personally grown to like them. But I can’t wait until Noctua has Chromax options available for when you need something that fits the look you are going for better.
Live Pricing: HERE
Live Pricing: HERE