The new Hydro X line looks very interesting. While FSP introduced the line as an affordable one compared to the Hydro G series, its members still perform pretty well overall. Their high MSRPs doesn't bother me too much since I am pretty sure that their retail prices will be much lower. My experiences with FSP's Hydro G models have shown me that these MSRP values will quickly be adjusted to make sure the Hydro X units are competitively priced. The HGX550 performs well with tight-enough load regulation on its major rails, satisfactory ripple suppression, and high overall efficiency. It also features one of the most efficient 5VSB rails I have come across thus far, and the number of cables and connectors FSP equipped it with will allow it to power a gaming system with two mid-end VGAs. The lack of modular cables might trouble some, but manufacturers tend to sacrifice them first in order to lower production costs for a more appealing retail price. A non-modular PSU can save you some money if you don't mind spending some time on routing all the cables out of sight during its installation, and you won't suffer from any efficiency losses and voltage drops due to modular cables. However, most of us nowadays are used to modular PSUs, which can make swallowing the idea of using one with nothing but native cables hard, especially if its MSRP is close to $100. Such a high MSRP for a non-modular 550 W PSU looks out of this world since one could get a fully modular 550 W unit of high quality for just as much. Just look at the Corsair RM550x that easily outperforms the HGX550 in almost every section. FSP should offer this unit at a much more affordable price to make it a competitive option. I believe a price of around $70-$75 to be much more fitting given how the HGX550 performs and what it features.

What gave me lots of trouble during testing is its really weird fan profile that is due to a poorly placed thermistor that provides temperature information to the fan-control circuit. FSP attached this thermistor to the main transformer instead of finding a way to monitor the +12V FETs' temperatures, which results in a lousy fan profile that has the fan run at an almost steady 1200 RPM throughout the PSU's entire operating range at normal operating temperatures. To make things worse, the fan also spins at close to 1200 RPM at light loads where the HGX450's fan only spins at 700 RPM. I received two HGX550 samples, and the fan behaved the same with both, which suggests that FSP should look into this matter as soon as possible. With a proper fan profile and a much lower price close to $70, I would have no problem whatsoever in recommending this unit since it uses reliable quality components and performs well overall.