BFG Tech MX 550W Modular Power Supply
Author: Shawn Knight
Editor: Rutledge Feman
Date: 02-05-2009
Provided by: BFG Technologies
Installation / Testing / Conclusion

Before installing the power supply in my test system, I first connected it to my CoolMax Power Supply Tester. Doing so answers a few questions up front. First, is the power supply functional or defective, and second, I get some useful information about the unit's voltages. Initial testing with the CoolMax PSU tester shows that all of the voltages are within spec.

I spent a little extra time routing cables and as you can see, I ended up with a very clean install. Even with the added time, I spent less than an hour removing my previous unit and installing the 550 MX. If aesthetics and a clean install are important to you, modular is certainly the way to go. It would be next to impossible to pull off this look with a non-modular system, as there would be a lot of unused wires in the case.

Below is a complete list of the test system specs.

Intel Core 2 Duo E7200
Cooler Master V8 Heatsink
4GB OCZ Reaper DDR2
Palit HD 4870 Sonic Dual Edition
Western Digital 74 GB Raptor 10,000 RPM SATA
Western Digital 120 GB 7,200 RPM
Creative X-Fi Sound Card
DVD Burner
SilverStone FT01 Case
2x 180mm Case Fans
1x 120mm Case Fan
Logitech G15
Logitech MX Revolution
Logitech G51 Surround Sound Speakers

I used a digital multimeter to obtain voltage readings. Since most power supplies correct any fluctuation in the current to the rails before our multimeters would even notice, we're unable to monitor every output in real-time simultaneously. To record idle voltages, I let the system sit idle in Windows for 20 minutes. For load voltages, I ran Prime 95 (one instance per core), OCCT, ATITool 3D View Fuzzy Cube, AIM, Winamp, Outlook Express and a few Firefox instances. This combination of programs put a nice load on the system. Below are some photos and the results from my testing.

Usage, Findings and Conclusion

Voltage monitoring shows that the 550w unit held up well and had more than enough juice to satisfy the test system's requirements. Most systems use much less power than many users are led to believe, so I had no doubts that 550 watts would be more than enough for this hardware configuration. The 3.3v and 5v lines only saw a fluctuation of .01, while the 12v VGA line tested showed a drop of .06 under load. The 4-pin Molex line tested only dropped .04 when stressed. All lines were well within spec and the small amount of fluctuation experienced is nothing to be concerned with.

The modular cable system will allow for a clean install and better airflow inside your case, since the unused cables can be removed completely. Some may not like modular cables since technically they aren't as stable as hard wired systems due to the extra "break" in each line, but I have never had a problem with them.

Speaking of the cables, there are more than enough Molex and SATA cables to go around, as well as two floppy connectors. The 20+4-pin ATX cable allows for backwards compatibility with older motherboards, as does the 4+4-pin CPU cable. Since this unit isn't geared for high-end video configurations, there are only two PCI-E cables supplied, with one being the 6+2-pin variety.

The unit itself is very quiet and the helper fan never turned on, suggesting sufficient cooling from the 120mm fan. Velcro straps and zip ties are also included with the retail package, although with the modular cable system, I didn't need to use any of these but they are a nice touch.

BFG Tech offers a five year warranty on this PSU, but note that you must register the product with them within 30 days of purchase to activate the warranty.

If you are on a budget or simply aren't a big gamer with an even bigger video card, the BFG Tech MX 550w Power Supply would make an excellent choice for nearly any circumstance. has awarded the BFG Tech MX 550w Power Supply our Seal of Approval.

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