It’s rumored that Seasonic is working on a passively cooled 1000W PSU to add to its Prime Fanless TX lineup, which could debut at CES 2026. Presumably, the upcoming power supply will adhere to the same 80 Plus Cybenetics Titanium certifications as the 600W and 700W offerings in the Prime Fanless TX series, which also include a 12-year warranty. News of the 1000W variant arrives from Cowcotland (via HardwareLuxx).
“PRIME Fanless TX utilizes the fanless technology, which eliminates the fan noise completely, ensuring truly quiet operation. The unit not only is rated to be Cybenetics Titanium efficient, but it also has the highest power output on the fanless power supply market at the moment. The power supply is ideal any situations that demand silence from the equipment.”
-Seasonic
With a power efficiency between 91% and 93%, these passively cooled PSUs offer the best of both worlds for silent power delivery and are fully modular as well. However, if the 1000W model features the same connectors, do not expect a 12V-2×6 option, as neither of the current models has this, which means that users with GPUs featuring that connector will need an adapter. As these are likely aimed at non-gaming scenarios that lack the aforementioned connector, it is probably a moot point for those applications where silence is the priority. It will also be interesting to see what the 1000W variant will be priced at, since the 700W version currently goes for a hefty chunk of change, as power supplies go, on Amazon. Below is a snapshot of current pricing for that model, along with its specifications from Seasonic, to give an idea of what to expect for the 1000W version.
Seasonic Prime Fanless TX-700 Specifications
| Cybenetics Efficiency Level | Titanium | |
| Cybenetics Noise Level | A++ | |
| Form Factor | ATX/EPS | |
| Dimensions | 170 × 150 × 86 mm | |
| Fan Information | Fan Size | Fanless |
| Cable Information | Modularity | Fully Modular |
| Cable type | Webbed cables (MB, CPU, PCIe) – Flat Black Cables | |
| Electrical Features | Operating Temperature | 0 – 45 °C (derating from 100 % to 80% from 40 °C to 45 °C linearly) |
| MTBF @ 25 °C, excl. fan | 100,000 hours | |
| AC Input | Full Range | |
| Protection | OPP, OVP, UVP, OCP, OTP, SCP | |
| Safety and Environmental | Safety and EMC | cTUVus, TUV, CB, CCC, BSMI, EAC, CE |
| Environmental Compliance | Energy Star, RoHS, WEEE, ErP Lot 6, REACH | |
| Warranty | 12 Years | |
| AC Input | 100 V – 240 V | |||||
| 9 – 4.5 A | ||||||
| 50 Hz – 60 Hz | ||||||
| DC Output | Rail | +3.3 V | +5 V | +12 V | -12 V | +5 VSB |
| Maximum Power | 20 A | 20 A | 58 A | 0.3 A | 3 A | |
| 100 W | 696 W | 3.6 W | 15 W | |||
| Total continuous power | 700 W | |||||
Discussion (3 replies)
Join Discussion →I have to be honest.... I don't know that I'd want that for a main PC. and for a SFF I would want more air movement and to orient the power supply to remove hot air from the case as well.
Not going to lie, there's got to be a pretty specific use-case scenario for this. Put it in a gaimg rig and that heat is adding to everything else, which also means the silent aspect is defeated since either CPU or GPU is going to have to deal with it, and one of those is likely to make some noise.
1K fanless is a feat.
I agree, seems a bit niche, as once you get that large other components all have fans that make the PSU negligible.
Still neat though.