Corsair HX620 620w Modular PSU
Published: 27th November 2006 | Source: Corsair | Price: |Load Testing
In order for the results from all current and future PSU reviews to remain fair and comparable, Overclock3D uses a custom built Power Supply load stress tester. The tester will be placing the following loads on each of the HX620's rails:
| +3.3v Rail||10a||20a|
| +5.0v Rail||10a||20a|
| +12v Rails||10a||10a x3|
As some power supplies produce obscure voltage outputs when running with 0% load, the Idle testing simulation will be produced by placing each rail under a small load similar to what would be expected from a mid-range PC. Load testing results are obtained by placing the unit under the maximum load selectable on the OC3D equipment without tripping the OLP (Over Load Protection) on the power supply.
During the +12v load testing, each of Corsair's three rails (rated at 18amps) were placed under a total load of 30 amps. As a result of this, each rail produced the same voltage output results across the board and therefore only necessitated a single graph as shown above. With a maximum voltage fluctuation of 0.02v, the HX620 shows that it is more than capable of producing stable power to any medium/high-end SLI or Crossfire setup.
Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester. These results may not be 100% accurate, but have proven to be extremely close to results obtained from professional equipment.
Increasing the load on the unit produced even more favourable results, with the HX620 managing 83.8% efficiency when being placed under a total load of 646 watts.
Possibly the hardest part of any PSU review is summarising the level of noise given out by the unit. The threshold for what is considered 'noisy' varies from person to person and therefore what I may consider a quiet unit, another person may consider extremely loud. A common way to resolve this issue is to use a dBA meter to measure the units noise level, however this doesn't take into account the pitch (type) of noise emitted and whether it is likely to irritate end users.
For this reason OC3D records all power supplies at idle and load in wav format for you to make your own informed decisions. All recordings are taken at 30cm away from the PSU and outside of a PC case. You will need to remember that noise levels will be reduced by varying amounts once the PSU has been installed inside your PC enclosure.
Idle Recording - Download
Load Recording - Download
At idle the HX620 was extremely quiet with the 120mm fan running at a very low RPM. As the load on the unit was increased, the fan gradually gained speed in order to counteract the extra heat produced by the PSU's components. Even at full load the HX620 managed to keep a good balance between the noise and heat output of the unit, proving that Seasonic's implimentation of a 60mm fan on their M12 PSU was not necessarily required.