All power, no fan! Seasonic is building a 1000W passive PSU

Seasonic plans to showcase a 1000W passive power supply at CES 2026

Seasonic is upping its passive PSU game. According to a report from Cowcotland, Seasonic has plans to create a new variant of its PRIME FANLESS TX power supply that can deliver users 1000 watts (1000W) of power. Today, this PSU is available with 600W and 700W models.

This new passive power supply is reportedly 80+ Titanium-rated and requires no cooling fans. To achieve this, Seasonic will need to overbuild this PSU and focus more on power efficiency and fanless cooling performance.

It is claimed that Seasonic plans to introduce this new 1000W PSU at CES 2026 in January. Like the company’s other fanless units, this new PSU will feature modular cables. It should also feature a 12-year warranty, like Seasonic’s other passive PSUs

(Seasonic’s PRIME FANLESS TX 750W power supply)

Building a 1000W passive PSU is a huge challenge

PSU cooling is a challenge. There’s a reason why almost all PSUs include fans. Most modern PC PSUs are “semi-passive”, which means that their fans are only turned on when necessary. This is usually when PSUs exceed 50% of their rated power. To build a passive PSU, manufacturers need to do one of two things. First, they need to minimise heat production. Second, they need to ensure that heat buildup isn’t a problem.

With an 80+ Titanium efficiency rating, this new PRIME series PSU is incredibly efficient. There is no higher efficiency rating available. A more efficient PSU generates minimal heat. While efficiency is important, careful testing and design are required to prevent heat buildup. When there’s no fan to fall back on, PSU heatsink design and component layout become more important than before. In other words, this PSU requires more design work, a robust passive cooling system, and overspecced components. This PSU will be fancy! Very fancy!

You can join the discussion on Seasonic’s plan to release a 1000W passive power supply on the OC3D Forums.