The Antec Earthwatts was installed into one of our standard mid-tower cases for testing. Because the cables are not modular, we had to do extra work so that the unused cables didn’t get in the way or impede airflow. Basically once you identify the cables you will need, tie the others off with a rubber band and stuff them in a incospicuous area of the case, like the hidden area between the PSU and the case.
The main motherboard line is the only cable that is sleeved, which keeps it from tangling with all the other loose wires. The 500W version of the EarthWatts also includes two PCI-E connectors (lesser models only have one). The cables are of adequate length for a mid-tower or desktop case, but may be too short for a full tower.
The Antec Earthwatts was allowed to “burn in” for one week before testing. Load was simulated by running 3dMark 2006 in a continuous loop, and load was measured using a power consumption gauge. A digital multi-meter was used to record accurate voltages from the PSU, as many software solutions can be very inaccurate, often outside a 10% threshhold. Since this PSU claims to be more efficient, the exhaust temperature was measured with an IR thermometer and compared against another major 500W power supply.
Test System
- Foxconn 975X7AB Motherboard
- Intel E6600 Core 2 Duo Socket 775
- 2GB OCZ XTC DDR2 PC2-4200 Gold Dual Channel memory
- XFX GeForce 7800 GT PCI Express Video card
- Zalman CNPS9700 NT Heatsink
- 3x Western Digital SATA Hard Drives
- Lian Li V1000 Black Aluminum Case
- Operating System: Windows Vista
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Based on these readings, the Antec EarthWatts power supply has very tight tolerances at all load levels. The 12v line dips into 2% tolerance levels, but just barely. Ultra, on the other hand, has variations up to 10%, which is the most a power supply should fluctuate. Ultra’s 12v lines are rather stable, which is what uses most of the power, and the margins for a 3.3v rail are razer thin. The exhaust of the EarthWatts was measured at 102 degrees, and the Ultra measured 104 degrees under full load.
