The Rosewill Hive 850W PSU Review

Hot Test Results

As we can see in the results displayed in the following tables, the Rosewill Hive 850W offers acceptable power quality considering its price range and performance class. The maximum ripple on the 12V line was 40mV under full load, a very good figure. However, the Hive 850W is not really fond of getting cross-loaded, as the ripple of the 12V line increased by over 50%. Nevertheless, 64mV is a mere half of the 120mV design limit. Voltage regulation could see some improvement, as we recorded a fluctuation of 3.4% for the 12V line and about 2.5% for the 3.3V/5V lines. On an absolute basis these are good figures, but relatively speaking high performance products nowadays rarely surpass 2%.

Meanwhile the Hive 850W's temperature rating of 40°C is not doing it any favors in our hot test. As we run our hot test at temperatures over 45°C, the Hive is operating outside of its comfort zone. Reducing the ambient temperature of our hotbox testing to base it around the Hive's 40°C is an option here, but ultimately we chose not to do so as any change for the Hive 850W in particular would mean that the results here would not be comparable with our previous reviews.

High ambient temperatures have a strong negative effect on the electrical performance of the Hive 850W. The energy conversion efficiency is reduced by an average of just 1.5%, yet the effect is stronger at high loads, where the performance of the Hive 850W was already suffering. Considering that this unit is rated at 40°C and we have over 50°C ambient temperature with the Hive 850W under maximum load, these are overload conditions for this unit and it shows, as the efficiency drop is over 2.4% and the internal temperatures are very high.

The high internal temperatures of the Hive 850W decrease the efficiency of its active components, creating a cascading effect that increases the heavy load temperatures of the Hive 850W even further. The lack of efficiency combined with the simplistic cooling design creates a major thermal load that cannot be easily dissipated, leading to heatsink temperatures nearing 100°C under maximum load. There is little that the small and plain heatsinks of the PSU can do under these conditions, leaving the fan to cope with the high thermal load. As a result, the fan reached its maximum speed, generating intolerable noise levels while the PSU was heavily loaded inside the hotbox.