About a year ago, I challenged myself. I wanted to know how small I could make a PC while packing in the highest-end gaming hardware money can buy, and that’s sent me on a bit of a journey.
I’ve made tweaks here and there, swapped out hardware, and endlessly fiddled with my fan curves. But finally, after many months and lot of money down the drain, it feels like my PC has reached its final form. And it all happened because I invested about $60 in a tiny Noctua cooler that’s completely changed my relationship with my small form factor (SFF) PC.
Meet the 92mm beast
OK, enough preamble. This mystery Noctua cooler is the NH-L9x65. It’s available in both Noctua’s chromax.black color option, as well as silver with one of Noctua’s iconic beige and brown fans. I chose the latter because I love the look — we exist — but it’s what this cooler has going on under the hood that stands out.
Get your weekly teardown of the tech behind PC gaming
It’s a low-profile cooler, clocking in at just 65mm tall, and that’s a requirement given that my PC is built inside of a Fractal Terra mini-ITX case — the best mini-ITX case you can buy, thank you very much. I wasn’t able to use a cooler this tall previously, as I tried cramming in an RTX 4090 and was only left with about 55mm of clearance for a CPU cooler. But a lot has changed since then.
Notably, Nvidia released the RTX 5090. This is a proper two-slot graphics card — at least for the Founder’s Edition model — freeing up a ton of extra space for a CPU cooler. Previously, I was using an ID-Cooling IS-55, which was just barely enough to keep the Ryzen 7 9700X in my PC cool. Jumping from the RTX 4090 to the RTX 5090 opened up more room, allowing me to get a taller cooler, and in turn, pack in a more powerful CPU (more on that in a moment).
The NH-L9x65 is a taller cooler, but it’s not a bigger cooler, and that’s why I love it so much. Instead of a standard 120mm fan, the NH-L9x65 uses one of Noctua’s slim 92mm NF-A9x14 fans. If you’ve worked with mini-ITX motherboards before, you know that’s a big deal. With Noctua’s cooler, I don’t have to fight with my case or the heatsinks built onto the motherboard, and that made properly installing it a breeze.
Due to how small mini-ITX motherboards are, you’re given a limited footprint for a cooler. In the case of something like the IS-55 I was using previously, the cooler actually had a portion of the heatsink clipped out to make room either for the RAM or the motherboard’s heatsinks. Not a problem on the L9x65. The cooler doesn’t protrude too far beyond the CPU socket, making the installation far easier.
The difference-maker is the performance, however. The NH-L9x65, despite its petite size, is one hell of a CPU cooler, and it’s completely changed my SFF rig.
Small PC, big performance
I settled for the Ryzen 7 9700X in the previous iteration of my PC. I intended to use the Ryzen 7 9800X3D, but given the space and cooler constraints, I decided to ditch the 3D V-Cache chip for a standard 8-core offering. The NH-L9x65 made AMD’s best gaming CPU a possibility, though, and the performance has been fantastic.
Here’s a taste. Below, you can see my temperatures with Noctua’s cooler, and the results are great. For a small form factor PC with a high-end gaming CPU known to run hot, I’ll take idle temperatures under 50 degrees Celsius. And although the temperature ramped up with an all-core Cinebench R24 load, it’s still well within safe operating temperatures. The chip also maintained its maximum boost clock of 5.2GHz across all cores during the run, which is mighty impressive.
| Idle (30 minutes on Windows desktop) | 44.1 degrees Celsius |
| Daily use (10 Chrome tabs, Discord, and Steam) | 63.8 degrees Celsius |
| Cinebench R24 all-core | 86.7 degrees Celsius |
These might seem a little warm if you’re accustomed to a full-sized desktop, but for a case as tiny as the Fractal Terra — and packing some power-hungry hardware — this is exceptional performance. I’ve seen the CPU break 90 degrees before, but only for a brief moment, and while I’m playing games, it rarely goes above 70 degrees.
Temperatures are great, but given the size of the NH-L9x65, I assumed it would make trade-offs in noise. This is a 92mm fan, after all, and the smaller you go on the fan, the more loud and annoying the whine is when the fan ramps up. But no. The NH-L9x65 is cool, but it’s also remarkably quiet given the hardware it has to cool.
| 0% fan speed | 42.2 decibels |
| 50% fan speed | 45.2 decibels |
| 100% fan speed | 59.1 decibels |
Decibel measurements need a bit of context. On a noise scale, 40 decibels is considered the average noise inside a house, so my measurement at 0% fan speed represents the ambient noise in my office. Even ramping up to 50% fan speed, the noise is barely audible over the sound of a normal room. For my use, the fan speed hovers between 50% and 70% while I’m working with a dozen or so Chrome tabs open, as well as Discord and Steam running in the background.
In practical use, that means I barely hear my PC while I’m working. That’s great.
When you push the fan hard — and it will get pushed hard while playing games — the noise ramps up quite a bit. Still, 59.1 decibels isn’t bad. On the decibel scale, this would be just below the noise of a normal conversation (no shouting) and just above the idle hum of a refrigerator. Basically, it doesn’t sound like a jet engine, even when the fan speed is spinning at its maximum RPM and the cores are fully loaded. I’ll take that any day of the week.
In my previous build, I was constantly fighting noise and temperatures, regardless of how much I tweaked my fan curve, and while using a weaker CPU. Now, I’m able to get better performance without worrying that my PC is going to take flight with how fast the fan is spinning. And that largely comes down to spending $60 on a new CPU cooler.
