The XP-650 is declared to support Rail Fusion technology which means joining several +12V outputs into one in case of overload. I wrote about this technology in the introduction to the article and in the section about the Corsair CMPSU-620HX. It means that there is no splitting of the +12V rail into several lines in this PSU. The PSU manufacturers’ marketing departments have already convinced quite a lot of users that there must be several +12V rail, so they now have to declare new technologies which come down to nothing else but the lack of other technologies. The matter of the splitting the +12V power rail into several output lines is all about ensuring user’s safety and has nothing to do with stability or output power of a power supply.

So, the PSU has four +12V outputs with a current of 20A each. The combined current cannot exceed 44A. As you may have guessed, there is actually only one +12V 44A power rail inside the PSU while the rest of the text on the label has nothing to do with the real technical characteristics of the product.

At a load of 630W the output voltage ripple amounted to 26 millivolts on the +5V rail, to 39 millivolts on the +12V rail and 25 millivolts on the +3.3V rail. There’s only high-frequency pulsation here.

The cross-load characteristic of this power supply looks beautiful. The output voltages do not even approach the 5% deflection anywhere in the allowable load range.

The XP-650 has two Globe Fan RL4G S0802512FHD fans, one in a translucent case with emerald highlighting and another made of ordinary black plastic. The fans are connected in parallel, so their speeds are regulated synchronously.

At loads below 300W the fans are rotating at a speed of 1800rpm. Although this speed is rather low for an 80mm, the fans in this PSU are quite distinctly audible at that. From a load of 300W onward (and sooner in a closed system case), the speed of the fans is growing up linearly until it reaches 2600rpm. The noise of the air passing through the PSU becomes rather irritating. I guess it is due to the densely ribbed heatsinks that obstruct the airflow.

The PSU is only 79% efficient. Its power factor is 0.66 at the maximum.

The Mushkin XP-650 power supply might be a good PSU to buy if it were not for its price. Priced at about $200, it is considerably more expensive than a majority of PSUs of similar wattage, including the above-described Corsair CMPSU-620HX. The Mushkin PSU doesn’t offer anything exceptional. It has a deplorably low efficiency for its product class and unhandy thick cables. That’s why I can’t recommend it to you for purchase, at least until the company have seen to these drawbacks and reduced the price to a competitive level.