The ASUS TUF Gaming 850W Gold PSU Review: Tough But Fairby E. Fylladitakis on August 31, 2023 9:00 AM EST
Cold Test Results (~26°C Ambient)
For the testing of PSUs, we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.
The overall efficiency of the ASUS TUF Gaming 850W Gold PSU is very good, with the unit easily meeting the 80Plus Gold requirements with an input voltage of 115V. Although the unit has its efficiency certification officially only with an input voltage of 115V, it would also pass the higher efficiency requirements and receive the 80Plus Gold certification with an input voltage of 230V if ASUS pursued it. The average nominal load range (20% to 100% of the unit's capacity) efficiency is 90.9% when powered from a 230 VAC source, which drops to 89.8% with an input voltage of 115 VAC. Generally speaking, the unit seems optimized for an input voltage of 230V, as there is a significant efficiency gap, especially at very high loads.
ASUS went with a semi-passive thermal design with an impressively lax cooling profile that has the unit operating fanless for more than half its entire load range. Once the fan starts, which would take a load of over 550 Watts at room temperature, it is barely audible. The fan speed quickly increases as the load reaches the maximum of the unit’s capacity but never becomes too loud. Conversely, the internal temperatures of the unit are allowed to climb significantly before the fan begins to spin, suggesting that ASUS’ engineers have a lot of faith in the resilience of this unit’s components.