Minisforum BD790i - InWin Chopin

Details

The InWin Chopin Pro is rated at 43mm heatsink height.

The BD790i heatsink height is 37mm.
I am adding a 15mm Noctua 120mm fan.
With the included FAN bracket, the fan assembly height is 18mm.

Note: MinisForum only includes M2.5x25mm screws for the fan.
I found M2.5x16mm flat head screws for the 15mm fan.

From the standoff, the Chopin has 48 mm of clearance.
With the PCB, the motherboard is 39mm. With the Fan, the height is 57mm.

I am missing 9mm.

The Chopin the mesh side panel is embossed by 8mm.

The fan needs to be moved back by 43mm to let the Chopin side panel slide in place. The fan will be held by a custom bracket.

The fan is able to clear the ram and a M.2 NVME riser.

The motherboard headsink is 92mm wide. A 92mm fan mounting option would have been nice.

The Chopin is always a tight fit!

I was considering using the Chopin MAX for its 54mm of clearance. This would bring 11mm additional height room.

However, it is likely that the fan would be under the back case edge. Using the back fan bracket may prevent fan removal.

Project Logs

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Final Build
Stanislas Bertrand • 06/24/2024 at 04:29 • 0 comments
After contacting support about the BIOS issue, I returned the motherboard.
I got a refund. I got a new unit from Amazon a few weeks ago.
With the delay, I opted for a 92mm fan build.
- 92mm fan area on heatsink: 52.90cm² / 53.13cm² (99.6%)
  - Estimated airflow (99.6%) 57.27 m³/h
  - Static pressure 2,11 mm H₂O
- 120mm fan area on heatsink: 54.63cm² / 89.72cm² (60.9%)
  - Estimated airflow (60.9%) 57.36 m³/h
  - Static pressure 1,53 mm H₂O
The aftermath math seems to indicate similar airflow, relative to cover heatsink area, however the static pressure is better with the 92mm fan.
The 92mm fan makes of an overall nicer build. The 14mm height allows for an 2mm acrylic support with 4 mounting holes.
There is small gap between the support plate and the heatsink. Perhaps air could be sealed a bit more to flow out the back.
When putting on the IO plate, I realized that the antenna connector are SMA rather than RP-SMA. Since the antennas are provided I understand the choice, however it needs to be noted that WiFi generally uses RP-SMA pigtail. I wanted to use small antenna screwed on the back directly thus had to change the pigtail which was very annoying. I would guess people are likely to connect other antenna and get bad performance since there is no pin connecting the pigtail signal to the antenna.
Overall the fit is quite nice.
I added a custom RED LED strip that can be controlled from the FAN PWM.
The thermals are acceptable with between 75°C to 90°C considering the 100W consumption of the CPU.
I noticed that under high boost the thermal get pretty high. However with all core loaded at 4.4GHz, the system hold around 80°C. I need to tweak the PWM curve.

The new motherboard does not have the BIOS issue.
The NVME are enumerated correctly with each 4 lanes at full speed (Gen4, Drive limited).
I had plan for a Ryzen 9 7900 build to be conservative with power and heat.
This build kind a match a Ryzen 9 7950X, in a 3.3L case!
The system is quiet when idle except for the PSU fan.
BIOS Settings
Stanislas Bertrand • 04/14/2024 at 01:39 • 2 comments

When main AC power is disconnected from the power supply, the system loses configuration.
Upon AC power connection, the system BIOS is reset and boot takes 1min 40sec.

Usually when such behavior is observed, it is a problem with the coin cell battery.
I have checked the coin cell battery and its connection to the motherboard.
The coin cell voltage is 3.3v and connection to the system is correct.
Is other user of BD770i / BD790i observing similar behavior ? Leave a comment !
I faced this issue directly when secure boot was preventing me from loading custom linux kernel module for the ITE IT8613E system monitoring.
The BIOS seems to reset every time AC power is connected which takes time and discard any custom settings.
By default secure boot is enabled. I would like to also retain custom fan configuration.
Motherboard Connector
Stanislas Bertrand • 04/14/2024 at 01:34 • 2 comments

The BD790i has 2 3-pin connector that are not documented.
The PJ3601 connector is next to the CPU 4-pin connector.
There is another 3-pin connector next the the USB 3.0 header.
Leave a message if you know details about those connectors.
One may be chassis intrusion detection.