We’re close to the finish line on Framework Desktop development. We’re now at the end of the DVT2 phase where we complete validation and finalize firmware and drivers. With that, we’re continuing our deep dive series, this time digging into the semi-custom 400 W Power Supply we integrated into the product. This may sound mundane, but it’s one of the more complex parts of the product. To align to our product philosophy, we used a standard FlexATX form factor. That means both that you can bring your own compatible power supply or re-use the one we designed in the future with any other ATX-compatible system. If you’re bringing your own, make sure to pick one that can handle at least 32.5 A on the 12 V rail.
Although the “peak” power demand of the AMD Ryzen AI Max processor is 140 W, it can actually pull hundreds of watts in millisecond-level bursts. Because there is no battery in the Framework Desktop to absorb this, we sized up the Power Supply to handle it and maximize performance. We worked with FSP, one of the biggest power supply makers in Taiwan and the manufacturer behind many other brands, to build a compact, high-efficiency, quiet design. We actually started with one of their higher wattage off the shelf power supplies, down-rated it to 400 W to focus on efficiency while allowing higher peak load, and customized it from there. We modified a few areas to optimize it for the core Framework Desktop use cases.
First, the fan. Because the FlexATX form factor is so small, there is only room for a 40 mm fan. We investigated swapping to Noctua’s 40 mm, but found that the air pressure was insufficient to cool the Power Supply. Instead, we looked through Delta’s catalog to find the ideal fan. We spent several sessions inside of an acoustic chamber listening to and measuring different Delta fans to choose the one that sounded best while pushing both enough CFM and enough pressure to handle full load at high ambient temperature. We also adjusted the Power Supply housing to have larger airflow openings than FSP’s stock design and added a duct to pull in cool air from outside the Framework Desktop case. We adjusted the fan algorithm as well. This is a hardware circuit that turns the fan on when the internal temperature of the power supply exceeds a certain threshold. During low system load, the fan stays off, and once the threshold is passed, the fan gradually ramps to the target RPM.
Beyond fan acoustic noise, we also improved electrical acoustic noise. High-power systems like this have massive current spikes that can result in inductor coils or capacitors chirping or buzzing. We worked with FSP to tune the component values and also add potting to substantially cut down on this noise. One last change was to make the Power Supply visually cleaner. We removed the cables that the Framework Desktop doesn’t use and made the power supply housing and cables black to match the rest of the interior.
All of this helps make the Framework Desktop modular, standards-based, efficient, and powerful. I’m sure that some of you reading the above want to use this power supply in other computers too. We’re making it available in the Framework Marketplace once we start shipping the Framework Desktop later this summer.
- We’re heading into the manufacturing ramp for Framework Laptop 12 and sending out press units for reviews shortly. Pre-orders are into Q3, but you can still get into Batch 0 and receive your laptop early by donating to Hack Club.
- Translucent Bezels for Framework Laptop 13 and USB-C Expansion Cards are now available in the Framework Marketplace. These look awesome.
Source: Framework
