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Silverstone SX300-B 300W SFX power supply, black finish, compact rectangular unit with 80mm fan visible on one side

Silverstone Technology

Silverstone SX300-B 300W SFX Power Supply

SKU CH-C66R-7F7M5

SFX power supply delivers 300W continuous output with 80 Plus Bronze efficiency and a silent 80mm fan rated at 18dBA

  • Chassis styleDesktop
  • 300 W continuous output at 40 °C
  • 80 PLUS Bronze efficiency reduces waste heat
  • Single +12 V rail delivers 25 A
  • 80 mm fan runs as low as 18 dBA
  • SFX form factor fits compact chassis

300W SFX power supply for compact builds

The Silverstone SX300-B delivers 300W of continuous power in the standard SFX form factor. It is suited to small-form-factor desktops and low-power servers that need reliable 24/7 operation. The single +12V rail provides 25A output for stable voltage delivery. This unit fits builds where space is limited and efficient power is required.

Bronze efficiency and quiet 80 mm fan

Certified to 80 PLUS Bronze, the supply runs efficiently at up to 40 °C operating temperature. An 80 mm fan spins at a minimum of 18dBA for silent running in noise-sensitive environments. Fixed black cables keep the interior tidy without modular connectors. The compact chassis suits desktop server installations with standard SFX mounting.

PCIe 6-pin and 8-pin connectors included

The bundle supplies one 6+2-pin PCIe connector for discrete graphics or add-in cards. No additional cables or software utilities are provided in the package. Builders needing multiple GPU power leads or modular cabling will need a different unit. The fixed harness simplifies installation in tight cases.

How it compares

Measured against everything we stock in Rackmount Server Cases, at today’s prices. Recalculated every night.

Price $90.99
Cheaper than about 91% of the 1,006 comparable items (median $222.49).

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Specifications

Size & build
Chassis styleDesktop

Questions about this item

What does the 80 PLUS Bronze rating mean for efficiency on this 300W SFX supply?

The 80 PLUS Bronze rating confirms the unit meets defined efficiency targets under typical loads, reducing waste heat and lowering running costs compared with unrated units.

What clearance does the 80 mm fan need inside an SFX chassis?

The unit follows the standard SFX form factor, so it fits any chassis with an SFX mounting cavity; the 80 mm fan exhausts through the rear grille and requires no extra clearance beyond the standard cut-out.

How do I connect the fixed PCIe cable to a graphics card that needs an 8-pin socket?

The fixed cable ends in a 6+2 pin connector; slide the 2-pin section alongside the 6-pin block to form an 8-pin plug, then insert it fully until the latch clicks.

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