Seasonic Focus GX-1000 V4 ATX v3.1 PSU Review

Summary

Seasonic’s updated Focus GX line, now compatible with ATX v3.1 and PCIe 5.1 standards, offers compact PSUs ranging from 750W to 1000W. Despite their small size, they feature a 135mm fan and an innovative OptiSink design to enhance heat dissipation and airflow. While the design improves cooling, the performance does not exceed that of the older GX-1000 model, with average efficiency and noise levels lagging behind competitors. Overall, the Focus V4 units exhibit decent performance but lack the exceptional efficiency and low noise seen in similar models from other brands, leading to concerns over their high price point.

Takeaways

• 😀 Seasonic's Focus GX line is updated to be compatible with ATX v3.1 and PCIe 5.1 standards.
• 😀 The Focus GX line includes models with 750W to 1000W capacities and features a compact 140mm depth.
• 😀 A 135mm diameter fan is used to maintain low noise levels despite the compact design.
• 😀 The OptiSink PCB design aims to improve heat dissipation and increase PSU reliability by eightfold.
• 😀 The PSU features a modular panel with eleven sockets, including a 12V-2x6 connector for high-power needs.
• 😀 The unit includes 16AWG gauge cables for lower voltage drops, and the connectors are spaced for better airflow.
• 😀 The Focus GX PSU uses a full-bridge topology on the primary side for increased reliability and efficiency.
• 😀 The cooling fan is sourced from Hong Hua, and the fan controller is programmable for better thermal management.
• 😀 The PSU's fan speed profile needs improvement, especially with varying load patterns during testing.
• 😀 While the PSU offers good ripple suppression and satisfactory transient response, its overall performance lags behind competitors in the same Wattage category.

Q & A

What new features were introduced in the updated Seasonic Focus GX line?

The updated Focus GX line is now compatible with ATX v3.1 and PCIe 5.1 standards. It also features a new OptiSink PCB design aimed at improving heat dissipation and airflow, which enhances the reliability of the PSU.

How does the compact design of the Seasonic Focus GX affect its performance?

Despite its small 140mm depth, the PSU maintains performance with a 135mm fan that helps keep noise levels low while still allowing effective cooling due to the improved airflow from the new PCB design.

What is the OptiSink design and how does it benefit the Focus GX units?

The OptiSink design introduces a new PCB layout that increases heat dissipation, contributing to enhanced reliability. It is claimed to offer an eightfold increase in heat dissipation compared to previous designs.

How does the Focus GX PSU manage its cooling?

The Focus GX PSU uses a 135mm fan and offers a semi-passive fan operation mode. The fan is controlled by a digital MCU that adjusts the speed based on the load, helping to maintain a balance between cooling and noise.

What are the key connectors available on the Focus GX PSU?

The Focus GX PSU has eleven modular sockets, including a native 12V-2x6 connector, and comes with various cables and connectors for EPS and PCIe connections, including 16AWG cables for lower voltage drops.

What is the significance of the 12V FETs being placed on the top PCB side?

Placing the 12V FETs on the top PCB side ensures they are directly in the airflow path from the fan, improving cooling efficiency and contributing to better thermal performance.

How does the power factor and efficiency of the Focus GX compare with previous models?

The Focus GX line's efficiency is not as high as previous models, particularly the GX-1000. The PSU falls short in terms of power factor and efficiency, especially at lower load ranges and with higher input voltages.

What issues were found in the fan speed profile during the tests?

The fan speed profile behaved unexpectedly during testing, with the fan starting at over 800 RPM and producing noise above 25 dBA even under low load. This behavior seemed to be inconsistent with the expected load patterns.

Why does the Focus GX show lower overall performance compared to competitors?

Despite its improved design, the Focus GX PSU falls short in areas like ripple suppression, efficiency, and transient response. The 12V rail voltage drops, poor load regulation, and higher than expected inrush currents contribute to its lower overall performance.

How does the Focus GX PSU perform in terms of noise output?

The Focus GX PSU generates average noise of around 28 dBA, which is low but not the quietest in its wattage category. Its noise output is relatively high compared to other PSUs in the same power range.