BFG Tech EX Series 1200 Watt Power Supply
Author: Frank Stroupe
Editor: Shawn Knight
Date: 06-16-2009
Provided by: BFG Technologies
Frequency Conversion Technology/Installation

BFG EX Series power supplies have features found on few power supplies on the market, and these features actually make the EX Series different from other power supplies. I'd like to spend a minute talking about these.

First, the BFG EX Series emulates smaller power supplies based on load:

High-end rigs utilizing multiple GPUs can use a fair amount of power, but rigs using two or three video cards spend a significant amount of time at idle. A 1200 watt power supply running at 20% is putting out 240 watts… even a three-way SLI rig at idle may only be using 150 or so watts. 80Plus testing includes tests at 20%, but the rig may spend much if not most of its time at well under 20% where nearly no power supply on the market is reaching 80% efficiency.

BFG's EX Series use “Frequency Conversion Technology”, which make them unique from other power supplies out there. Frequency Conversion utilizes a “resonant mode controller” to constantly modulate switching frequencies depending on the load. This allows the power supply to effectively emulate smaller capacity power supplies, making the unit more efficient at lower loads. So while other 1kW+ power supplies may not be as efficient running at less than 20% of their capability, the BFG EX power supply is efficient with loads as low as 10% of the PSU's capability.

In other words, the average 1200 watt power supply is running very inefficiently while the rig is at idle. With Frequency Conversion, the BFG EX-1200 at low load thinks that it is, say, a 450 watt PSU, so instead of running at a very inefficient 10-15% or even less, the EX is effectively running at 25-35% or more, a range that power supplies are much happier at and run more efficiently.

Second, BFG EX Series power supplies demonstrate high efficiency across a wide array of loads:

Rather than using typical Schottky rectifier diodes for 12v regulation (which really aren't the best solution for low voltage applications such as PC power supplies), BFG uses “synchronous rectification”, consisting of diodes and MOSFETs, which provide additional efficiency across the entire range of loads.

Third, unlike many power supplies, the BFG EX Series has no minimum load requirement on any rail:

Today, most PC power is drawn from the +12v rail, and conversion is done by MOSFETs on the motherboard and video card to get +3.3v and +5v, rather than drawing from the PSU's +3.3v and +5v rails. This can cause problems with many power supplies as they often have minimum load requirements on all rails, and that may not be met on the lower voltage rails. The EX Series attains +3.3v and +5v in the same way, by DC to DC conversion using MOSFETs, which also allows for no minimum load requirement on any rail.

Finally, the EX Series' independent +5vSB circuitry improves efficiency in standby:

Most power supplies utilize the same primary circuitry capable of handling upwards of 1500W of power for a mere 15W of standby power. The EX Series has a completely separate primary and secondary circuitry just for the +5VSB. This makes the EX more efficient when the computer is in standby mode.


Test Rig:
Intel i7 920
Gigabyte EX58-UD4P X58 motherboard
Crucial Ballistix Tracer Blue DDR3-2000 6GB triple channel memory kit
Asus GTX260 Matrix geForce GTX 260 video card
OCZ EliteXStream 800 Watt PSU (for comparison purposes)
Ikonik Ra X10 Liquid Aluminum Liquid Cooled full tower
Windows Vista Ultimate 64-bit

Of course, installing a power supply is very simple. Place the unit in the case, connect the necessary cables and hide what's left the best you can.

I needed only the cables that were hard-wired. The SATA cable was long enough that I was able to connect the hard drive and optical drive on the same cable.

  Sponsors Links

  Sponsors Links