![[H]ardOCP](/images/blank.gif){kind=small}
- Date:
- Wednesday, October 03, 2007
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
$50 Power Supply Roundup
We went to Newegg and purchased five US$50 computer power supplies that we thought should be solid buys. But what happens when you ask these PSUs to put up its advertised power numbers in heavy usage conditions? You might be surprised what 50 bucks gets you now days.
Load Testing
For those of you that are curious as to some of the reasoning and equipment behind our PSU testing program here at HardOCP, we have put together a living document that shares a lot of the behind the scenes of the program. The testing we are conducting today is exactly as described in that document and will begin with a range of loads tested at 120v input including our torture test and then move on to the same set of tests at 100v input but without the torture test.
120v Load Testing Results
100v Load Testing Results
Test #1 is equal to approximately 25% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #1 equal to 122w by loading the 12v rails to a combined 7a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.5a. The results of Test #1 at both 120v and 100v are decent. The unit is in specifications but the efficiency is nothing to write home about at 75.31% (100v) and 76.37% (120v).
Test #2 is equal to approximately 50% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #2 equal to 234w by loading the 12v rails to a combined 14a, the 5v rail to 7a, the 3.3v rail to 4a, the +5vsb to 2a, and the -12v to 0.5a. Test #2 showed a huge drop in output voltages for the 12v rails as they plummeted ~0.3V from Test #1 levels at both 120v and 100v. The efficiency of the unit at 120v though has moved up greatly to 82.68% while the 100v efficiency is suffering from the lower AC input voltage at 78.78%.
Test #3 is equal to approximately 75% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #3 equal to 377w by loading the 12v rail to 21a, the 5v rail to 15a, the 3.3v rail to 10a, the +5vsb to 2a, and the -12v to 0.5a. Test #3 sees the 12v DC output voltages rebound to ~12.11v from their sudden drop during Test #2. The unit’s efficiency has moved down at both 120v and 100v now as is typical. The efficiency is now standing at between 80.21% (120v) and 77.73%(100v).
Test #4 is equal to approximately 100% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #4 equal to 498w by loading the 12v rail to 29a, the 5v rail to 20a, the 3.3v rail to 12a, the +5vsb to 2a, and the -12v to 0.5a. In the final regular test we have an interesting set of results. The 120v values are in specification, albeit both the DC output voltages have dropped and so has the efficiency (77.81%), but is performing well enough. As soon as we switch over to the 100v testing the Basiq simply shuts down after running for a few moments. Once it is reset to a lower load the unit will come back on but it will not complete Test #4 at 100v no matter how much we try to nurse it through the test.
The Torture Test
The final component of our load testing involves our 8 hour torture test. This test is meant to simulate what gaming or hardware enthusiasts might encounter when they use their systems for extended periods of time under stressful conditions such as 3D gaming or long term stability testing and benchmarking. We do not suggest using your power supply at 100% loads for extended periods of time and our torture test does reflect this. We load the PSU being tested to ~80% of its rated capacity for 8 hours at a temperature of 45c. This is outlined in our testing methodology should you wish to have more information.
The Torture Test is equal to approximately 80% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #3 equal to 399w by loading the 12v rail to 26a, the 5v rail to 9a, the 3.3v rail to 8a, the +5vsb to 2a, and the -12v to 0.5a. The Antec Basiq units were able to complete the Torture Test as when they shut down in Test #4 at 100v they did so in a controlled manner. This resulted in a unit that posted numbers very similar to the closely related Test#3 at 120v as is typical.
Transient Testing
The Transient Testing portion of this review marks the first revision to our living testing methodology. Readers can read more about this inclusion in our testing here in our methodology section, but briefly we will be examining the response of the power supply to a short duration load such as a RAID array spinning up or load change due to power draw from video cards etc. Ideally we would not see a deflection from the baseline voltage output when this occurs but that is simply not the case for the majority. We will be using the ATX12v specification for transient response as a guide.
The Transient Load Tester adds an additional 9.25A to the 12v rail for 10ms and an additional 3.75A to the 5v rail for 10ms at 25% total load and 50% total load.
Transient Load Testing Results
Test #1 is equal to approximately 25% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #1 equal to 122w by loading the 12v rails to a combined 7a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.5a before the addition of the transient load. The results of Test #1 show a peak change of ~300mV when the 12v rail is loaded and ~110mV change when the 5v rail is loaded. During the 12v load an unloaded 12v rail shows a peak change of ~150mV while the 5v rail shows a peak change of ~50mV. The 12v drop under load of ~300mV is the largest we have seen to date but remains in specifications as the base line 12v reading was well above 12v.
Test #2 is equal to approximately 50% of the rated capacity of the Antec Basiq 500w at 45c. This makes Test #2 equal to 234w by loading the 12v rails to a combined 14a, the 5v rail to 7a, the 3.3v rail to 4a, the +5vsb to 2a, and the -12v to 0.5a before the addition of the transient load. Test #2 shows a peak change of ~300mV when the 12v rail is loaded and ~120mV change when the 5v rail is loaded. During the 12v load an unloaded 12v rail shows a peak change of ~110mV while the 5v rail shows a peak change of ~50mV. These values closely match the results we saw in the first transient test and again remain within specification.
Load Testing Summary
Overall the load testing for the Antec Basiq 500w was acceptable for the tests it was able to complete. However, the unit cannot be given a clean or complete pass as it was unable to complete Test #4 at 100v. Additionally, the units efficiency while still acceptable is not up to par with many more expensive units currently on the market but when it is in its "sweet spot" the unit is easily 80% efficient at 120v AC input. The Transient Testing for the unit was a clean pass but with a bit of note as the ~300mV change we saw on the 12v rails is the largest to date but could still be surpassed by other units in the roundup. The unit remained within specification during the transient test but much of that is due to the unit having a high 12v set point.