Seasonic Gold Series X-750 Power Supply Review
Introduction and Features
Seasonic has built a stellar reputation for producing some of the best PC power supplies on the market today. In their relentless pursuit to continuously improve their products, Seasonic has recently upgraded the X-650, X-750 and X-850 units to provide quality performance for PC enthusiasts who seek reliability, tight voltage regulation, and high efficiency. The following list details the specific enhancements and differences between the earlier KM2 models and the new X-650/750/850 KM3 models.
• 12V Line Regulation improved to ±2% instead of ±3%
• S2FC/S3FC Selector Switch allows end user to select fan control mode of choice
• Flat Black DC Cables: easier to install, better airflow, and good appearance
• Increased number of CPU/PCI-E cable options
• New KM3 models use Full Bridge topology versus Half Bridge in KM2 for better reliability and efficiency
• MOSFETs relocated to Daughter Card instead of main PCB for improved efficiency, cooling and safety
• KM3 uses High Current Connectors (9A, 85°C) for added security and reliability
Seasonic 80Plus Gold X-Series Features
80Plus Gold The X-Series Gold 650/750/850 power supplies are certified in accordance to the 80PLUS organization's Gold standards, offering performance and energy savings with up to ≥90% efficiency and a true power factor of greater than 0.9 PF.
Full Modular Design (DC to DC) The Seasonic X-Series power supplies feature an integrated DC connector panel with onboard VRM (Voltage Regulator Module) that enables not only near perfect DC-to-DC conversion with reduction of current loss/impedance and increase of efficiency but also a fully modular DC cabling that enables maximum flexibility of integration and forward compatibility.
Seasonic Hybrid Silent Fan Control An industry first, advanced 3 phased thermal control balances between silence and cooling. The Hybrid Silent Fan Control provides three operational stages: Fanless, Silent and Cooling Mode. In addition, a selector switch is provided to allow you to select between Seasonic S2FC control, without fanless mode or S3FC fan control with fanless mode.
Sanyo-Denki San Ace Silent Fan The world-renowned Sanyo Denki ball bearing fans are made of the highest quality components to insure maximum quality and performance. The use of spoon shaped high-density plastic fan blades with smoothed leading edges, strict tolerance ball bearings and precision copper axel are just some features to ensure ultra-low noise performance and quality."
Seasonic 80Plus Gold X-650/750/850 PSU Key Features:
• 80Plus Gold certified high efficiency ≥90%
• 7-Year manufacturer's warranty worldwide
• Fully Modular Cable design with flat ribbon-style cables
• Seasonic DC Connector Panel with integrated VRMs
• DC-to-DC Converter design
• Hybrid Silent Fan Control (3 modes of operation: Fanless, Silent and Cooling)
• High-quality Sanyo Denki San Ace dual ball bearing fan with PWM
• Tight voltage regulation (±2% +12V rail)
• Supports high-end graphic cards
• Conductive polymer aluminum solid capacitors
• High reliability 105°C Japanese made electrolytic capacitors
• X-850W: PCI-E 8/6 pin x 6, SATA x 10, 4-pin Molex x 5, FDD x 1
• X-650W/750W: PCI-E 8/6 pin x 4, SATA x 10, 4-pin Molex x 5, FDD x 1
• High current Gold plated terminals with Easy Swap connectors
• Active PFC (0.99 PF typical) with Universal AC input
PSU Testing Methodology
Establishing an accurate load is critical to testing and evaluating a PC power supply. PCPerspective’s power supply test bench can place a precise DC load on the PSU under test. Each power supply is tested under controlled, real-world conditions up to its maximum rated load (at 40ºC), using both 115 VAC and 240 VAC line voltage. Our current suite of tests includes:
• DC Load Regulation
• AC Ripple and Noise
• Differential Temperature
The Seasonic Gold Series X-750 power supply was evaluated on both features and performance. A full range of equipment was used to test the power supply under controlled load conditions.
• (2) CSI3710A Programmable DC load (+3.3V and +5V outputs)
• (4) CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• (2) 200W Precision resistor load bank (+12V5 and +12V6)
• Switchable precision resistor load bank (-12V and +5VSB)
• Agilent 34401A digital multimeter (Accuracy ±0.0035% vDC)
• Extech 380803 Power Analyzer (Accuracy ±0.5% of full scale)
• DS1M12 "StingRay" digital oscilloscope (20M S/s with 12 Bit ADC)
• Powerstat Variable Autotransformer, 1.4 KVA, 0-140 VAC
• Extech Model 407738 digital sound level meter (Accuracy ±1.5 dB)