FOCUS Series

Overview of the Seasonic FOCUS Series

Key Features and Benefits

Seasonic FOCUS series power supplies are highly efficient, with 80 PLUS® Gold and Platinum certifications. They also feature a compact form factor, a fully modular cable system, and quiet operation thanks to an intelligent fan control system (Hybrid Silent Fan Control). 

Seasonic FOCUS PSUs support modern power standards and have built-in protections (OCP, OVP, SCP, OTP, OPP). We always put the safety of our products and your PCs first. 

All power supplies in this series are manufactured with premium components, ensuring stable and reliable operation for many years. At Seasonic, we offer a warranty of up to 10 years, which demonstrates our confidence in the high quality of our products.

Who Is the FOCUS Series Designed For?

The Seasonic FOCUS GX and PX series are designed for a wide range of users who need a reliable, efficient, and compact power supply. It is an excellent choice for gamers, enthusiasts, professionals, and anyone building a powerful system with a single GPU. 

The FOCUS series is characterized by high efficiency (up to 90%) and quiet operation thanks to hybrid fan control. They are fully modular, support modern ATX 3.1/PCIe 5.1 standards, and are compact in size, with a depth of only 140 mm. The previous FOCUS Plus models didn’t have these updates. Thanks to FOCUS PSUs characteristics, you can easily integrate this power supply even into cases with limited space. 

The FOCUS series is often recommended as the optimal choice for everyday builds. 

Available FOCUS Series Models

FOCUS GX – Fully Modular Gold Certified Models

The Seasonic FOCUS GX series is an updated line of 80 PLUS® Gold Gold-certified power supplies with a rated power of 1000W, 850W, and 750W. All support ATX 3.1 and PCIe 5.1 standards and are equipped with a native 12V-2×6 (12VHPWR) cable to power modern GPUs. 

Seasonic FOCUS Gold models feature a fully modular design that simplifies cable management and improves ventilation in cases. Their dimensions are 140 mm × 150 mm × 86 mm, making them a compact solution in the ATX device category.

The FOCUS GX design incorporates innovations such as OptiSink technology. This means that the power components are fixed directly to the copper surface of the PCB, which increases internal space by 48% and improves airflow.

This series is ideal for modern gaming or work systems that require a reliable power supply with high scalability.

FOCUS PX – Platinum Efficiency with Silent Operation

The Seasonic FOCUS PX series is 80 PLUS® Platinum-certified PSUs. That means that this series provides high energy efficiency of up to 92%. They are equipped with a 135 mm fan with FDB bearings, which operates in silent mode (fanless mode) at low loads. This means that even under heavy system loads, this power supply unit ensures virtually silent operation. 

FOCUS PX power supplies support the latest ATX 3.1 and PCIe 5.1 standards, including a 12V-2×6 cable for powering modern GPUs, and come with a 10-year warranty from Seasonic. The fully modular cable system reduces clutter in the case and improves airflow there. 

The FOCUS PX series is an excellent choice for users looking for an efficient, quiet, and reliable solution for modern gaming PCs and workstations.

FOCUS SGX – Compact SFX Models for Small Builds

The Seasonic FOCUS SGX series is are compact SFX format power supply. They were designed primarily for small form factor PCs, such as mini-ITX and micro-ATX. These power supplies offer high efficiency, quiet operation, and stable performance. So users who want to maximize space don’t have to compromise. 

All models are 80 PLUS® Gold certified, providing up to 90% efficiency at 50% load. They are also equipped with a 92mm fan with fluid dynamic bearings (FDB). The compact dimensions of 125 mm × 100 mm × 63.5 mm allow the PSU to be installed in confined spaces without losing power. 

Performance and Efficiency

80 PLUS® Certification Levels

The Seasonic FOCUS series of PSUs offers various levels of 80 PLUS® certification. Like the following ones. 

1. The FOCUS PLUS GOLD and FOCUS GX models are 80 PLUS® Gold-certified, guaranteeing an efficiency of around 90% at 50% load. 
2. The FOCUS PX series features a higher level of efficiency – 80 PLUS® Platinum, with up to 92% efficiency at 50% load. 
3. The compact FOCUS SGX models are also 80 PLUS® Gold-certified with an efficiency of around 90%. 

The higher the certification level, the more economical and stable the power supply is. 

Fan Control and Acoustic Performance

The Seasonic FOCUS series (both GX and PX) is equipped with digital hybrid fan control (Hybrid Silent Fan Control). This technology provides a combination of quiet operation and efficient cooling of PC components.

In other words, Seasonic FOCUS GX/PX offers a balanced combination of quietness and efficiency. All thanks to the following factors:

1. Fanless Mode up to ~30% load.
2. The noise increase is gradual: up to ~29 dBA at medium loads, up to ~36 dBA during intensive operation.

Users choose hybrid mode because it runs quietly, especially when the system isn’t overloaded. This only confirms the efficiency of Seasonic FOCUS power supplies. 

Thermal Management and Hybrid Mode

The Seasonic FOCUS series of PSUs is equipped with an intelligent fan control setup – Hybrid Silent Fan Control. Essentially, it optimizes the balance between effective cooling and low noise levels. This system operates in three modes:

1. Fanless Mode, when the fan does not operate at loads up to 30%.
2. Silent Mode, when the fan runs at minimum speed to ensure quiet operation at medium load.
3. Cooling Mode, when the fan runs at high speed for efficient cooling under high load or high temperature.

Some FOCUS series models are equipped with a fan control button. That little but convenient option allows users to manually switch between modes to achieve the desired noise and cooling levels.

Build Quality and Components

Internal Components and Capacitor Quality

The Seasonic FOCUS GX and PX series of power supplies are notable for their use of premium internal components. They ensure reliable, stable, and long-lasting operation of both the power supply and your PC. 

The input is equipped with effective EMI filters with X and Y capacitors, chokes, and a varistor, which efficiently clean the current before its primary conversion. The main capacitor in the APFC circuit is a Japanese Rubycon 400 V with a capacity of 470–560 µF and operates at temperatures up to 105 °C. 

Japanese Nippon Chemi-Con and Nichicon capacitors are used in secondary circuits and DC-DC modules. It is also rated for 105°C, which ensures high-quality ripple filtering and longevity. 

Key power components, including MOSFETs and diodes, are implemented in a highly efficient Full Bridge LLC topology with synchronous DC-DC converters. All capacitors are located directly on the boards, without additional elements in the cables, which improves their reliability. The soldering quality is rated as very high. 

Protections and Certifications

The Seasonic FOCUS GX and PX series power supplies have a complete set of built-in protection systems. These include:

1. OCP (overcurrent protection), 
2. OVP (overvoltage protection), 
3. UVP (undervoltage protection), 
4. OPP (overload protection), 
5. SCP (short circuit protection), 
6. OTP (overheating protection). 

These features ensure stable and safe system operation even under adverse conditions. FOCUS GX models comply with ATX 3.0/3.1 and PCIe 5.1 standards, feature a fully modular design, and a compact 140 mm × 150 mm × 86 mm chassis. The 10-year warranty from Seasonic is also provided. 

They are certified to the 80 PLUS® Gold standard, which ensures efficiency of around 90% at 50% load. In turn, FOCUS PX models have even higher efficiency, confirmed by 80 PLUS® Platinum certification (~92% at 50% load). 

All units in the series are additionally tested using the Cybenetics system, which confirms both their energy efficiency (ETA Gold/Platinum) and low noise level (Lambda A- or Standard++).