Seasonic offers four models under their G series: 360 W, 450 W, 550 W, and 650 W, all featuring the 80 Plus Gold certification. We’ve already reviewed the 360 W model, which proved to be a winner. Let’s see if the 550 W version follows in the same footsteps.

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Figure 1: Seasonic G-550 power supply

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Figure 2: Seasonic G-550 power supply

The Seasonic G-550 is 6.3” (160 mm) deep, using a 120 mm ball-bearing fan on its bottom (ADDA AD1212MB-A70GL, the same used on the 360 W model).

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Figure 3: Fan

Differently from the 360 W model, the Seasonic G-550 has a modular cabling system with six connectors: two for video card power cables and four for peripheral and SATA power cables. The unit comes with the main motherboard cable and an ATX12V/EPS12V cable permanently attached to it. They use nylon sleeves that come from inside the unit. This power supply comes with the following cables:

• Main motherboard cable with a 20/24-pin connector, 21.2” (54 cm) long, permanently attached to the power supply
• One cable with two ATX12V connectors that together form an EPS12V connector, 21.2” (54 cm) long, permanently attached to the power supply
• Two cables, each with one six/eight-pin connector for video cards, 23.6” (60 cm) long, modular cabling system
• One cable with four SATA power connectors, 16.9” (43 cm) to the first connector, 5.1” (13 cm) between connectors, modular cabling system
• One cable with two SATA power connectors, 13” (33 cm) to the first connector, 5.1” (13 cm) between connectors, modular cabling system
• One cable with three standard peripheral power connectors, 16.9” (43 cm) to the first connector, 5.1” (13 cm) between connectors, modular cabling system
• One cable with two standard peripheral power connectors, 13” (33 cm) to the first connector, 5.1” (13 cm) between connectors, modular cabling system
• One adapter to convert a standard peripheral power connector into a floppy disk drive power connector

All wires are 18 AWG, which is the correct gauge to be used.

The number of connectors is perfect for a 550 W power supply.

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Figure 4: Cables

Let’s now take an in-depth look inside this power supply.