SFF pc project 2.0

I wrote a article a while back about a PC built using 3D printing and unconventional components. Since I started to attend university at OSU, I did not have a good PC even though I do have a really good mac (M1 Pro, 14''). I use many Windows applications and having a dedicated windows computer is something important for me. 

I want to learn solid works to create 3D models for the use of laser cutting and 3D printing and would like to move away from Sketchup. However this is not possible with MacOS. In addition, I cannot play games, like Forza horizon or Asseto Corsa that only supports Windows only.

In addition, I would like to really like to explore Linux in a serious way. I will like to build a x64 machine that has a AMD graphics card in order to use linux well (something like a RX6500xt). I currently use a 1660ti graphics card for the build but will like to move to AMD in the near future.

I want to make another SFF pc, but this time with more typical components, significantly more computing power, and with a better aesthetic

Parts selection:

CPU: Intel i7 9700

GPU: Nvidia GTX1660ti

Motherboard: Asus Z370i ITX

RAM: 16GB x 2 DDR4 3200 from Crucial (was Silicon power 8GB x 2 DDR4 memory, for a total of 16GB RAM)

Power supply: Enhance ENP-7660B (was a FSP500-30AS, the one from the Intel NUC 9, had to modify it)

The constraints:

Just like last time, there are also difficult constraints on this project. The graphics card and also CPU is actually given to me by a really kind friend - who gave me a HP omen 875 desktop computer for me to mess around with - although missing RAM and a SSD. While the system works somewhat well, I really am a big fan of small form factor computers. I believe that a computer that could be miniaturized should be, and that ATX is really only reserved for higher TDP/multi CPU systems where such a small system is not practical in terms of cooling.

So I decided that I wanted to pursue what I really wanted - to make a 2.0 version of my computer case. I would like to cram all that hardware into a small, light, quiet, and powerful package that I can take anywhere I want and move in and out of my dorm easily. I really do enjoy the notion of a SFF pc as you can upgrade any component when a new generation comes out down the line at your own pace rather than buying a new laptop. 

Unfortunately like last time, I face financial constraints. Although this is the most difficult part of the project, it is actually what makes the project extremely intriguing and really fun. It forces me to do things in a unconventional way (such as modifying a power supply to save over 100 dollars that performs better than power supplies that you can buy at that price) is something I do enjoy doing. I would like to spend the least amount of money as I can and get the best bang for the buck. In order to reduce cost, I will sell components that I am not using for this project (such as the old PSU and motherboard) to reduce the cost of costly PC components further.

Lastly, I would like to keep the computer case as compact as possible. This is going to be more difficult as unlike the previous build, there is a flexATX power supply built into this computer - unlike the external power supply solution used in the past. Thus cooling, layout, and mounting of the components is crucial for the success of the project.

Executing the idea: Component choice

The motherboard:

The final motherboard choice was a Asus Z370I ITX motherboard. At first, I bought a Gigabyte H370N motherboard from eBay for 60$. It seemed good at first until the board arrived. Upon trying to boot the board, it would just spin up the fan for 10 seconds straight and then shut off, bootlooping this sequence. 

I then got a Asus motherboard and will sell the Gigabyte one. The Asus motherboard did not appear to work well at first (seems like a ram compatibility issue), but a BIOS update solved it completely and the system is running extremely stable and well here.

Picture of the motherboard, with RAM and CPU installed

Quick test setup

The power supply:

The power supply is the most interesting part of this build since I went with a rather unconventional route. I choose to use a flexATX power supply as they have the higher power density and also the least volume compared to other form factors such as SFX and ATX. With this reduction in size, cooling is challenging and would lead to alot of noise due to the use of high RPM server grade fans to move enough air in order to dissipate heat off the internal power supply components. I find that power supplies from Delta are extremely loud as of my experience, but such power supplies from Enhance electronics are very quiet in comparison due to the power supply being 90+ (compared to 80+ gold certification of the Delta PSU).

However, such power supplies are expensive. And I mean extremely expensive. A ENP-7660B will cost around 160$ which is way too much in my opinion. And even then I don't think I need 600W of power as well. So I did some research and found the FSP500-30AS, which according to anecdotal discussion on forms is a really quiet flexATX power supply, that can be picked up for as little as 30$.

I was contemplating on if I wanted to modify a power supply as I didn't want to risk damaging my motherboard. But I was swayed by the offer when the eBay seller offered me the power supply for 10$. This means that I am paying 21 dollars in total for a power supply (with shipping) - so I have nothing to lose if I test the PSU on a unused motherboard and check my wiring very carefully.

In the end the power supply worked and I stress tested the device for 30 hours. It worked well and did produce some heat (up to 40 degrees). This is expected as the device also passively dissipates heats off the components.

Scraping off some of the PCB mask to tap out 5V out from this power supply

The routed out wires

Exposed wires before heat-shrinking

First test run, you can see the wire job I did

Stress test with the GPU

Cooler:

The final thermal solution for this design is a total of 2 120mm fans. One is on top of the CPU cooler (Thermalright 120-X67), and the other is a exhaust fan (also from Thermalright). Both fans can spin up to 1800 rpm under full duty cycle and can get audible (not super loud though) under full load. 

CPU Cooler: AXP-X67

Case fan: TL-12015B

The fan solution is controlled by fan-control software on windows. This is done to have more precise control over the fans and also allow the speed of the exhaust fan to change based on both the temperature of the CPU and GPU, whether one is hotter.

Link to software here: https://getfancontrol.com/

GPU riser:

Link here: https://www.amazon.com/dp/B0CGTL3LFW?ref=ppx_yo2ov_dt_b_fed_asin_title

Parameters: PCIE 3.0, X16, 200mm length

IEC extender cable for PSU:

Link here: https://www.amazon.com/dp/B0B24ZYJ8W?ref=ppx_yo2ov_dt_b_fed_asin_title

Parameters: Screw hole to right, 0.6m length 

Final product:

CAD: case was designed in Sketchup.

GPU side view

Motherboard side view

Front view: notice the mesh layout on the front. This is done for the flexATX cooling when I get my EMP7660B power supply (after I come back from China)

Back view, notice how the bottom supports for the GPU mount also acts as the threaded holes that retains the screws for the IEC input plug

Top view, notice the 120mm fan and also the cooling hole cutouts for the flex ATX power supply

Bottom view - there are also holes for the intake of the PSU.

It took 1 whole day in to complete in terms of cutting and assembly.

Making the case:

Learning how to use the mill to cut the make-beam extrusions (this was a practice run). I greatly appreciate Ross (staff of the makerspace) for teaching me how to do this!

A picture of me using the mill, making the length precise and doing finishing passes

Using the meter saw to make a rough cut of the beams

Using a 80W laser cutter at the makerspace to cut the 5mm thick acrylic

3D printing the GPU mount in PETG - Bambu labs 3D printer

Case assembly photo 1

Case assembly photo 2

Final product without components:

Final product:

Project update.

For the sake of safety, the power supply was changed to a server grade, 600W power supply (Enhance ENP-7660B) that was modified professionally to a modular power supply. I was scared that the power supply will fail, especially with the extra current draw from the 5V rail. In addition, I didn't like the incompatibility with the ATX standard, with regards to a lack of a PWR-OK and -12V rail, which I am afraid will create issues down the line. I thus replaced the power supply for the above reasons.

Since the PSU was 600w and was significantly greater than the maximum power draw of the components, I added a "powerbus" port, which was a 12V output that can output power to peripherals. I use this port to power 2 monitors (dual monitor setup) and a speaker system. This is true small form factor as everything is powered off 1 IEC connector, no additional power bricks!

In addition, 2 USB 3.0 front header connectors were added. It was mainly added for the sake of aesthetics but also serves some functionality, despite one of the connectors being very unstable.

Direct cooling for the front panel was added, allowing the PSU to suck cool air directly from outside the case and expel warm air through the top of the case via the 40mm cooling fan, assisted by natural convection of air.

RAM was upgraded from 16gb to 32gb as well. 

In addition, I added a additional 500gb SATA ssd from Samsung to store data, such as games and VM which does not require the speed of the main NVME boot drive.