Noctua sent us two new prototype coolers, and these are the absolute game-changers for the Arm desktop market. Or at least for those trying to put Arm CPUs into a desktop to use as a workstation or a server. The Noctua NH-D9 AMP-4926 is the company’s 4U offering, while the Noctua NH-U14S AMP-4926 is the big 140mm option for best cooling performance. In either case, these are huge steps up from the 2U passive coolers we have seen in the market to date. Once they are out, they will make Arm desktops finally a mainstream option along with the ASRock Rack ALTRAD8UD-1L2T.
Previous State of Coolers
When the ASRock Rack ALTRAD8UD-1L2T arrived both on Newegg and the STH lab, there was a 2U passive heatsink option.
While some folks were screaming to get the bundle, the fact is that the 2U passive heatsink is tough to integrate into a desktop. One can 3D print an airflow guide with fan mounts, but it is far from being easy to plug in and use.
I also knew that Noctua had a line of coolers coming, and those are much easier to integrate.
Noctua NH-D9 AMP-4926 4U
The first, and what will ultimately be the most exciting one for servers is the Noctua NH-D9 AMP-4926 4U cooler.
This cooler has two heatpipe towers and two fans.
This is a fairly standard Noctua layout but with a cooling plate for the Ampere Altra socket. As a quick note, on both the Noctua coolers the coverage on the CPU heat spreader is much better.
Installed on the ASRock Rack ALTRAD8UD-1L2T we can see that this has standard front to back chassis airflow.
The advantage here is that the 4U height fits in most chassis. It also allows for relatively easy access to the eight DIMM slots around the CPU socket.
Our sense is that this will be the Altra cooler to get just because it is small enough to fit in most cases and it is plenty to cool the Altra/ Altra Max CPUs.
Noctua NH-U14S AMP-4926
The Noctua NH-U14S AMP-4926 is the big one. The NH-U14S is a popular cooler for many different sockets, but the AMP-4926 tells us this has been adapted to the Ampere Altra (Max.)
One big difference with the NH-U14S is just the height. Many desktop cases can take 165mm+ coolers, but when it comes to server cases, 4U cases will not fit this cooler.
The installation is easy since this is the AMP-4926 specific version.
Here we can see the big change in the ASRock Rack ALTRAD8UD-1L2T. The cooler is so big that it has to be top-to-bottom oriented instead of front-to-back. In most 4U workstation/ server chassis, this is not what we would want from an airflow perspective.
The size of the cooler also gets close to the two innermost DDR4 slots.
Overall this is a massive cooler, but if you are building in a traditional consumer desktop-style chassis, then this is a great option since normally in those cases there is a top exhaust fan.
Having used three coolers with the ASRock Rack ALTRAD8UD-1L2T at this point, the takeaway is clear. The current $1500 Newegg bundle (Newegg Affiliate link) with the motherboard and Ampere Altra Q64-22 (64 core / 2.2GHz) CPU is good, but the 2U passive heatsink is going to be borderline useless for most of our readers. These two Noctua options are game changers. They bring quiet cooling in familiar form factors.
When I first saw the ASRock Rack ALTRAD8U-1L2T, I told both the ASRock Rack and the Ampere folks that this was a winner, but it needed coolers. The Altra chips are not super high power, so liquid coolers are not necessary in desktop cases. These Noctua coolers are prototypes, but they are built on proven platforms so we expect them to be available soon-ish. Once they are, the ASRock platform is going to be awesome for those who want an Arm server platform in either a desktop or 4U chassis.