Seasonic Explains How It's Making A Fanless 1000W PSU For Silent PCs
Building a PC is not all that difficult, but assembling a totally silent (or even near silent) rig? That takes a little more research and finesse. It can also require making compromises, but to ensure that the power supply unit (PSU) is not one of them, Seasonic confirmed it's in the process of designing a fanless and ultra-efficient 1,000W PSU for silent, high performance builds.
Fanless power supplies have been around in the consumer market for a long while, but not at 1,000W. Instead, PSU makers have focused on making higher wattage PSUs as quiet as possible through a combination of efficiency goals, fan selection (like when Seasonic teamed up with Noctua), and semi-passive operation. That's to say, the fan only kicks on when the PSU reaches certain load and temperature thresholds, similar to how a lot of custom GPUs operate. A fan curve, basically.
To be clear, the model that Seasonic is working on is totally fanless.
As spotted by our friends at FanlessTech, the folks at Cowcotland recently caught up with Seasonic at an event to celebrate 50 years in the business, which explained that it's already able to operate PSUs in fanless mode at a 50% load. That means if you take a 1,200W PSU, it's "basically fanless below 600W."
So how is Seasonic making the leap to 1,000W in a fanless form factor? The company explains that it's leveraging advances in things like OptiSink, which is the company's proprietary internal design, that have resulted in lower temps.
"OptiSink was introduced at Computex 2024, as a first step to rehaul the entire PCB layout and manufacturing of Seasonic power supplies. The idea behind the process was to improve the cooling inside the power supply, which was achieved by increasing the internal space to facilitate better air movement. Internal components such as MOSFETs and heatsinks were not only reorganized but made smaller to reduce the footprint of these components," Seasonic explains.
The latest version of OptiSink (version 2.0) updates the PCB layout to incorporate "Surface Mount Technology," or SMT (not to be confused with simultaneous multi-threading in CPUs).
"During the manufacturing process the SMD MOS (metal–oxide–semiconductor) and the SMD heatsinks are directly soldered onto the PCB, which greatly reduces production errors, material usage, and electricity costs. Additionally, metal cooling caps are placed over the MOS to further improve cooling," Seasonic adds.
It also includes a larger heatsink and thermal past injection to fill the gaps between the MOSFET and heastink as a secondary heat dissipation path. According to Seasonic, OptiSinc 2.0 reduces MOSFET temperatures by up to 20%.
Hitting 1,000W in a fanless design would be impressive. Getting there with an 80 Plus Titanium designation is even more so, as it requires maintaining 94% efficiency at 50% load and 90% efficiency at 100% load. It's the highest certification for consumer PSUs (there's also an 80 Plus Ruby tier for redundant data center applications).
We'll have to wait and see when it comes out and how much it costs. In the meantime, check out our PC power supply buyer's guide on what to look for when shopping for a PSU.
