XtremeComputing has posted a review on the MGE XG MAGNUM 500W Modular PSU

This is a rock solid supply. Also the temperatures only went up after the overclocked load test. This is a good indication about how efficient the powersupply is. I am not certain about the 105W reading, but it could be accurate with that graphics card. Even with Dual 7800GTX and an FX-57, I have my doubts that more than 400W would be sustained for a long period of time.

MGE XG MAGNUM 500W Modular PSU