Mounting a powerful fanless computer
No computer had been quiet enough for me, until I mounted a completely fanless one.
Parts
- Case:
Cougar Blazer
This case has a great airflow. It also can be easily modified, as it uses screws instead of rivets.
I removed the top and front metal plates to improve airflow, and bent the plate with the power button (to have it easier to get my hand inside the case). I also removed the plates for 2.5" and 3.5" drives, and a few other parts that didn't seem necessary to me.
Since I'm not going to use any PCIe cards (that would kill the airflow), I could cut most of the back plate of the case, having better airflow, and also allowing me to manipulate the interior easily.
I won't use the USBs in the case (I never trust them), so I cut the USB cables (I couldn't remove them). I removed the cable for the case leds.
I put the case above a metal stand with holes in it, to further improve airflow.
- Motherboard:
MSI z790 ACE
I chose an E-ATX board because components have more separation, which makes for a better cooling.
Also, I want my computer to last many years, so I can give it away when I stop using it and it will still work for someone else for a long time. This high-end board has good quality components, which will hopefully survive many years.
I'm not interested in having so many connections. I'm only using the PCIe 5.0 M.2 SSD, and none of the SATA or PCIe slots. If there was a board that had the quality of this one with less connections, I'd probably go for it.
A feature I thought I wouldn't be interested in, but which I have come to appreciate very much: a 2-digit 7-segment display indicating the CPU temperature at all times after POST, which serves as a debug code during POST. However, there's no way to turn off the display only after POST, when I'm no longer interested in monitoring the temps.
As always, there's also crap in this board. For some reason motherboard producers believe we want a Christmas tree instead of a computer. This board has two of them; one on top of the I/O, and one on top of the chipset. The one on top of the I/O is removed easily: unscrew the back plate of the board, then the I/O panel. A large plastic panel will come out easily, after you disconnect the cable for the LEDs. For removing the one in the chipset, you'll also need to unscrew the back plate. Then unscrew the M.2 "shield", and the chipset metal block. When you have the metal block separate, you'll need a blade to separate the plastic cover, and a metal one, and then you'll be able to get rid of the screen itself. All of that is glued (and I bet that glue isn't even conducting heat), so it'll be hard to remove, but you can't break the aluminum block, so it should be easy. After you clean all the adhesive, screw it all back again.
- CPU:
- Contact frame: Thermalright LGA1700-BCF
To learn about why you'd want a contact frame, have a look at these reviews:
This one from Thermalright seems to be easy to mount, according to <https://youtu.be/k9TH7TeDZM8?feature=shared&t=173>, while having good performance.
- CPU: Intel i9-13900T
The best consumer CPU from Intel CPU, but the underclocked variant.
I thought I would go for AMD this time, but in the end I went for Intel because it had the lowest TDP for a powerful CPU.
Intel has the 'T' variants of CPUs, which is just an underclocked version of their normal CPUs. This is interesting because the base TDP goes as low as 35 W. Under load, it can go up to 106 W, so there's room for performance. If I need to compile a project, it'll go wild for a few seconds, or few minutes for huge projects, and then go back to low-power mode.
I disabled hyperthreading, and the performance improved considerably (and temps went down). For my use case, it's a useless feature, I believe.
I also don't need so many cores, and would probably be fine with the number of cores of an i7 or i5. What interests me more of the i9 is the huge cache. I found that it was really significant for some tasks in tasks that I needed to run many years ago, and now I look for the CPUs that have the larger cache, which usually happen to have more cores too.
In the BIOS, I limited the CPU temperature to 70 °C (the default is 100 °C). The performance drop isn't important, and the lifetime of the motherboard and CPU will increase. For comparison, building a Linux kernel v6.4 with `make -j8` takes 15 minutes with the limiter at 100 °C, and it takes 16:30 with the limiter at 70 °C.
Even though only 8 cores are "performance" cores, and the other 16 are "efficiency" ones, they are all useful for performance tasks. Building a kernel with `make -j8` takes 16:30 minutes, and building it with `make -j24` takes 9 minutes (and the computer remains responsive).
- Cooler: Noctua NH-P1
I don't think there's much to choose from (the only passive one from Noctua). I always use Noctua coolers, as they are the best. This one is great as well.
You can mount the cooler in 4 positions (every 90°). Of course, the fins should go vertical, which leaves us with only 2 positions: with the fins on top of the left MOSFET heatsink, or with the fins on top of the RAM. I put it to the left, on top of the MOSFET heatsink. That leaves the RAM uncovered, so it's easier to change it if I ever need. Also, in such a low power system, the MOSFETs shouldn't ever be overheating, so I prefer leaving more room for airflow for the RAM sticks. Also, in this position, the CPU cooler is closer to the back of the case, where it'll have better access to fresh air.
- Thermal pad: Thermal Grizzly Carbonaut
I don't like messing with paste, so I use thermal pads. I don't get the best performance, but it's already quite decent, and it's clean and simple. 100% recommended.
Pastes also have a limited lifetime, and you need to replace them, while pads should live basically forever.
- Contact frame: Thermalright LGA1700-BCF
- GPU: No thanks!
An integrated GPU is enough for me. And it produces less heat. Also, a PCIe card would break the airflow.
- RAM:
Crucial Pro 32 GB Kit (2x16) DDR5-5600 UDIMM
I tried other vendors in the past. I don't recommend G-Skill. They lied in the spec, and you had to read the entire datasheet to find that the actual speed was less than the one in the box. To reach the speed specified in the box, you had to use XMP (which is overclocking).
I also tried Corsair for a laptop, and it was good.
But since Crucial is part of Micron, and they are one of the three memory producers (with SK Hynix and Samsung), and you can't buy as easily from the other two, Crucial has become my go-to brand for memory.
Also, I prefer the Pro version, since the price difference isn't that much. Crucial likely uses their best memory for producing these, and since I want it to last for long, I prefer these. Also, they come with a heatsink.
Long ago I found that 16 GiB isn't enough for me. I could use 64 GiB, but it's more difficult to find in stock. 32 GiB kits are much more common (and cheap).
- SSD: ATP I-Temp NVMe pSLC PCIe Gen3 M.2 2280 SSD N750Pi 320 GB (p/n: AF320GSAJA-8BBIP)
I want a very reliable and fast SSD. Large storage is nice, but I don't really need that much. 1 TiB would be ideal, but I can live with a bit less.
SLC would be ideal for reliability, but it's too expensive, and is very limited in space. Pseudo-SLC (pSLC) drives have almost the same durability, but are way cheaper, and can use 3D-NAND, so they come in slightly larger sizes.
I want to use the M.2 slot in the motherboard which connects directly to the CPU, for maximum performance, so I need an M.2 PCIe NVMe drive.
This drive is the largest one I've found, with 320 GB. It also seems to be really fast, according to the datasheet. And since there's no cache, I expect this speed to hold for full-drive writes.
At 6.4 PB for the TBW (total bytes written), this drive is virtually immortal (if I'd write the entire drive every day --which is not going to happen--, it would last for 54 years).
It's only around 6x the price per byte of a Crucial T700, but accounting for the longer lifespan, and faster speed, I'm willing to use it where I don't need 1 TiB. I don't like this trend of packing more bits per cell in SSDs losing speed and durability.
Being a PCIe gen3 drive, the controller runs quite cold, so you don't need a heatsink.
- PSU:
Seasonic PRIME Fanless PX-450
For PSUs, I only trust Seasonic. Bad PSUs kill hardware.
I calculated that I only need around 150~200 W, so the smallest PSU would work. 450 W is the smallest one that Seasonic has.