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Advanced Transient Response Tests
For details about our transient response testing, please click here.
In the real world, power supplies are always working with loads that change. It's of immense importance, then, for a PSU to keep its rails within the ATX specification's defined ranges. The smaller the deviations, the more stable your PC will be with less stress applied to its components.
We should note that the ATX spec requires capacitive loading during the transient rests, but in our methodology, we also choose to apply a worst case scenario with no additional capacitance on the rails.
Advanced Transient Response at 20% – 20ms
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.101V | 11.775V | 2.70% | Pass |
| 5V | 5.034V | 4.948V | 1.70% | Pass |
| 3.3V | 3.344V | 3.211V | 3.99% | Pass |
| 5VSB | 5.050V | 5.011V | 0.78% | Pass |
Advanced Transient Response at 20% – 10ms
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.099V | 11.797V | 2.50% | Pass |
| 5V | 5.034V | 4.946V | 1.75% | Pass |
| 3.3V | 3.344V | 3.210V | 4.02% | Pass |
| 5VSB | 5.050V | 4.999V | 1.01% | Pass |
Advanced Transient Response at 20% – 1ms
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.098V | 11.816V | 2.33% | Pass |
| 5V | 5.033V | 4.938V | 1.90% | Pass |
| 3.3V | 3.344V | 3.202V | 4.24% | Pass |
| 5VSB | 5.050V | 4.988V | 1.23% | Pass |
Advanced Transient Response at 50% – 20ms
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.090V | 11.968V | 1.01% | Pass |
| 5V | 5.025V | 4.939V | 1.72% | Pass |
| 3.3V | 3.334V | 3.192V | 4.26% | Pass |
| 5VSB | 5.001V | 4.957V | 0.87% | Pass |
Advanced Transient Response at 50% – 10ms
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.085V | 11.958V | 1.06% | Pass |
| 5V | 5.025V | 4.934V | 1.82% | Pass |
| 3.3V | 3.334V | 3.193V | 4.22% | Pass |
| 5VSB | 5.001V | 4.948V | 1.06% | Pass |
Advanced Transient Response at 50% – 1ms
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.087V | 11.913V | 1.44% | Pass |
| 5V | 5.025V | 4.938V | 1.73% | Pass |
| 3.3V | 3.334V | 3.192V | 4.26% | Pass |
| 5VSB | 5.001V | 4.942V | 1.18% | Pass |
This PSU's transient response is mediocre at 12V, quite good at 5V, average at 3.3V, and fine at 5VSB. We would like to see better results here, especially at 12V, the most important rail.
Turn-On Transient Tests
In the next set of tests, we measured the PSU's response in simpler transient load scenarios—during its power-on phase. Ideally, we don't want to see any voltage overshoots or spikes since those put a lot of stress on the DC-DC converters of installed components.
Everything went well in our turn-on transient tests, with no notable spikes or voltage overshoots.
Power Supply Timing Tests
There are several signals generated by a power supply, which need to be within specified ranges (as set by the ATX spec). If they are not, there can be compatibility issues with other system parts, especially mainboards. Currently, the PSU's power-on time (T1) has to be lower than 150ms and the PWR_OK delay (T3) has to be between 100 to 150ms, so that it can be compatible with the Alternative Sleep Mode.
| T1 (Power-on time) & T3 (PWR_OK delay) | ||
|---|---|---|
| Load | T1 | T3 |
| 20% | 36ms | 134ms |
| 100% | 36ms | 134ms |
This PSU's PWR_OK delay is within the 100-150ms region, so it supports the alternative sleep mode recommended by the ATX spec.
Ripple Measurements
Ripple represents the AC fluctuations (periodic) and noise (random) found in a PSU's DC rails. This phenomenon significantly decreases the lifespan of the PSU's capacitors, because it causes them to run hotter. A 10-degree Celsius increase can cut into a cap's useful life by 50%. Ripple also plays an important role in overall system stability, especially when overclocking is involved.
The ripple limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V, and 5VSB).
| Test | 12V | 5V | 3.3V | 5VSB | Pass/Fail |
| 10% Load | 8.0 mV | 12.7 mV | 14.4 mV | 4.3 mV | Pass |
| 20% Load | 8.6 mV | 12.6 mV | 12.0 mV | 4.3 mV | Pass |
| 30% Load | 12.7 mV | 13.4 mV | 12.2 mV | 4.9 mV | Pass |
| 40% Load | 10.7 mV | 13.3 mV | 12.6 mV | 4.9 mV | Pass |
| 50% Load | 9.9 mV | 13.6 mV | 15.9 mV | 5.2 mV | Pass |
| 60% Load | 9.9 mV | 13.7 mV | 15.3 mV | 5.4 mV | Pass |
| 70% Load | 9.8 mV | 14.5 mV | 15.3 mV | 5.5 mV | Pass |
| 80% Load | 10.0 mV | 14.4 mV | 15.8 mV | 6.0 mV | Pass |
| 90% Load | 10.0 mV | 15.7 mV | 17.4 mV | 6.5 mV | Pass |
| 100% Load | 15.8 mV | 16.2 mV | 19.1 mV | 7.3 mV | Pass |
| 110% Load | 15.6 mV | 16.9 mV | 19.8 mV | 7.8 mV | Pass |
| Crossload 1 | 8.6 mV | 13.4 mV | 13.6 mV | 8.5 mV | Pass |
| Crossload 2 | 9.3 mV | 12.6 mV | 14.0 mV | 8.1 mV | Pass |
| Crossload 3 | 9.2 mV | 12.6 mV | 12.8 mV | 7.9 mV | Pass |
| Crossload 4 | 15.2 mV | 16.3 mV | 19.2 mV | 10.6 mV | Pass |
Ripple suppression is fine on all rails here. The 5V rail might have the highest ripple among all other PSUs, but still, 16mV is a low value, given the operating conditions.
Ripple At Full Load
Ripple At 110% Load
Ripple At Cross-Load 1
Ripple At Cross-Load 4
EMC Pre-Compliance Testing – Average & Quasi-Peak EMI Detector Results
Electromagnetic Compatibility (EMC) is the ability of a device to operate properly in its environment without disrupting the proper operation of other nearby devices.
Electromagnetic Interference (EMI) stands for the electromagnetic energy a device emits, and it can cause problems in other nearby devices if too high. For example, it can be the cause of increased static noise in your headphones or/and speakers.
EMI emissions are high in some regions on this PSU, with both AVG and Peak detectors. To be more precise, we measured seven spikes with the AVG and four with the Peak detector.
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