Seasonic has introduced its fourth iteration of Focus GX series power supplies with several new updates, including a new PCB layout and smaller MOSFETs. However, the main update Seasonic has incorporated is its all-new OptiSink technology, which has a revamped and improved cooling design.
Seasonic has coined the term OptiSink for its latest thermal solution for power supplies. OptiSink "increases internal space by approximately 48%, facilitating better air movement." According to the PSU maker, the extra space available allows OptiSink to exchange heat at a "significantly" faster rate, which boosts efficiency.
Optisink does this by changing how the power supply components are installed and making additional improvements to the cooling aspects of the power supply. Seasonic's new tech takes advantage of "modern surface mounting technology with direct soldering of components" and a fully automated manufacturing process "that minimizes human error."
The main design change with OptiSink is the introduction of PCBs used to power and cool the Metal-Oxide Semiconductors (MOS) powering the PSU. Seasonic's new tech takes advantage of PCBs by installing the MOS directly onto the copper surface of the PCB through soldering. This was done to "harness the superior thermal conductivity of copper." OptiSink differs massively from Seasonic's older implementation, which uses screws and thermal pads to mount the MOS onto aluminum heatsinks —completely lacking PCBs and any copper material.
This design has enabled Seasonic to massively reduce the footprint of many of its power supply components. The heatsinks alone are substantially smaller than Seasonic's previous design iterations, taking up only a very small amount of space on the PCB they help cool. The new heatsinks can also dissipate heat in any direction.
As the image above demonstrates, Seasonic's OptiSink tech drastically changes the layout of its GX Focus 2024 power supplies compared to the previous generation. Most of the components have been moved to multiple PCBs installed on the borders of the unit, opening up space in the middle of the unit. As previously mentioned, the heatsinks have been massively altered, now featuring a significantly smaller footprint.
Seasonic's v4 (2024) Focus GX lineup is purportedly one of the first (if not the first) power supply lineups to use OptiSink technology. Seasonic states that OptiSink will be introduced into all future power supply models.