The FSP Hydro G 750W Power Supply Review

Hot Test Results

As we can see in the tables below, the FSP Hydro G 750W can deliver good electrical performance under stress. Our instrumentation recorded a maximum ripple of 40mV on the 12V line, a good figure for a PSU of this class. Similarly, the voltage ripple on the 3.3V and 5V lines is 26mV and 22mV respectively. The filtering is however strange, as the PSU's output power quality degrades at both high and low loads, unlike the vast majority of designs which only degrade as the load increases. The voltage regulation is adequate, at 2.8% for the 12V line, 3.3% for the 3V line and 2.9% for the 5V line.

A high ambient temperature has a substantial negative impact on the electrical performance of the Hydro G 750W PSU. The average nominal load (20-100%) efficiency drops by 1.4%, while the maximum efficiency now is 90.6% at 50% load. Nevertheless, the drop is balanced across the entire load range and only slightly greater at maximum load, indicating that the components are not being overly stressed.

Due to the high ambient temperature, the fan of the Hydro G 750W PSU started with a load of 210 Watts this time and, naturally, began accelerating much quicker than before. Acoustics are being sacrificed but the Hydro G maintains comparatively low operating temperatures, surpassing 80°C only on the small secondary side heatsinks and under maximum load. Apparently, FSP does want this unit to remain quiet under normal operating conditions, but they are more than willing to sacrifice that acoustic comfort when the conditions are harsh in order to ensure the longevity of the PSU itself.