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SilverStone SFX ST45SF 450 watt Power Supply Review

Manufacturer: Silverstone

Introduction and Features

If you are in the market for a solid SFX form factor power supply for a Micro ATX Media Center or Home Theater PC that will support a high-end graphic card, the SilverStone ST45SF deserves a very close look!

SilverStone has a well earned reputation among PC enthusiasts for providing a full line of high quality enclosures, power supplies, cooling components, and accessories.  SilverStone recently added a new 450W power supply in the SFX form factor to their PSU line up.  The SFX form factor is frequently found in Micro ATX Media Center PCs and Home Theater PCs.

SilverStone SFX ST45SF PSU

Here is what SilverStone has to say about the ST45SF: "After successfully revolutionizing both HTPC and SFF market segments with innovative chassis designs, SilverStone engineers continue their push for advancement in these categories by releasing a true upgrade-worthy small form factor power supply, the ST45SF. This SFX unit is compatible not only with chassis that use SFX power supplies but also in smaller ATX chassis with the included adapter bracket. Despite its small size, the ST45SF has features that one would expect from an elite ATX power supply such as 80 PLUS Bronze level of efficiency, temperature controlled fan, 50°C temperature rating, and reliability for 24/7 operation. Enthusiasts oriented features are also present with single +12V rail and 8pin/6pin PCI-E connectors to fully support multi-GPU systems. For SFF users and SilverStone, the ST45SF is more than just an upgrade, it is an important milestone for the DIY desktop computer."

SilverStone ST45SF Main Features:
•    Supports standard SFX form factor and ATX (via included bracket)
•    450W continuous power output at 50°C and rated for 24/7 operation
•    80 PLUS Bronze level efficiency (82%~85% efficiency at 20%-100% load)
•    Class-leading single +12V rail with 36A capacity
•    Silent running 80mm fan (18dBA minimum)
•    Single PCI-E 8-pin and dual PCI-E 6-pin connectors
•    Active PFC

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 2,000 watt DC load on the PSU under test.  Each power supply is tested under controlled, real-world conditions up to its maximum rated load, using both 115 VAC and 240 VAC line voltage.  Our current suite of tests includes:

•    DC Load Regulation
•    DC Line Regulation
•    DC Cross-load (unbalanced load)
•    AC Ripple and Noise
•    Power Factor
•    Efficiency
•    Differential Temperature
•    Noise

The SilverStone ST45SF 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)
•    Extech MultiMaster MM570 digital multimeter (Accuracy ±0.02%)
•    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)
•    Custom PC60 enclosure to simulate real-world operating conditions


February 17, 2012 | 07:12 PM - Posted by techjohn (not verified)

Very good review. There seem to be a few power supplies out now in this form factor that are competing with this unit. After reading this review, I think I would only buy a power supply that was 80 plus certified. It gives me a warm feeling that somebody other than the manufacturer looked at the product and certified that it works the way it's suppose to.