As you can see from the graphs, the MX Series 550W is rather low down, although not very far from the rest of the mainstream pack. At 20 per cent load its efficiency is quite good - marginally better than the latest competition - the rest are notably a little behind the competition.
Conclusions and Value
£73 is a lot to shell out for a 550W PSU there's no doubt about it. That said, Corsair's VX550W is now a not inconsiderate £69 but isn't modular, while Seasonic's S12II 500W is also the same price.
Other modular PSUs like the BFG MX Series include OCZ's ModXStream 600W, which can be had for even less than the above at £68. However, Corsair's very popular yet ageing modular HX 520W is a whopping £78, but most places sell it for over £80. By that standard, the BFG looks good value.
We think that BFG could have saved on a more optimised design though - we feel the rear 60mm is unnecessary considering the availability of 13.5mm fans now and no other PSU requires it. The only other serious PSU we've seen use this strategy is the older Seasonic M12 700W.
BFG throws in a considerable five year warranty, but like its graphics cards, only if the product is registered with BFG within the first 30 days, otherwise it's a year only! That's understandable though and five years is more than Enermax and Seasonic's three year warranties. It matches Corsair VX/HX series as well as OCZ, although OCZ has the slight advantage with its Powerswap.
BFG's large metal shell feels a little vacant and empty for the size but loaded it works well enough, plus it's damn quiet to boot. The modular plugs are very nice, but there's a distinct lack of attention to real detail all over. Overall, we feel the performance, design and value of the BFG MX Series 550W isn't bad, but could be better: it has a few admirable features, and works perfectly fine, but doesn't excel in any particular area.