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Transient Response Tests, Ripple Measurements and EMC Pre-Compliance Testing
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 the 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 extra capacitance on the rails.
Advanced Transient Response at 20% – 200ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.112V | 12.020V | 0.76% | Pass |
| 5V | 4.969V | 4.824V | 2.92% | Pass |
| 3.3V | 3.342V | 3.102V | 7.18% | Fail |
| 5VSB | 5.031V | 4.974V | 1.13% | Pass |
Advanced Transient Response at 20% – 20ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.111V | 11.996V | 0.95% | Pass |
| 5V | 4.969V | 4.796V | 3.48% | Pass |
| 3.3V | 3.342V | 3.055V | 8.59% | Fail |
| 5VSB | 5.031V | 4.976V | 1.09% | Pass |
Advanced Transient Response at 20% – 1ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.109V | 12.000V | 0.90% | Pass |
| 5V | 4.969V | 4.795V | 3.50% | Pass |
| 3.3V | 3.342V | 3.042V | 8.98% | Fail |
| 5VSB | 5.031V | 4.974V | 1.13% | Pass |
Advanced Transient Response at 50% – 200ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.062V | 11.969V | 0.77% | Pass |
| 5V | 4.946V | 4.794V | 3.07% | Pass |
| 3.3V | 3.326V | 3.072V | 7.64% | Fail |
| 5VSB | 4.982V | 4.923V | 1.18% | Pass |
Advanced Transient Response at 50% – 20ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.061V | 11.949V | 0.93% | Pass |
| 5V | 4.946V | 4.762V | 3.72% | Pass |
| 3.3V | 3.326V | 3.033V | 8.81% | Fail |
| 5VSB | 4.982V | 4.911V | 1.43% | Pass |
Advanced Transient Response at 50% – 1ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.060V | 11.952V | 0.90% | Pass |
| 5V | 4.946V | 4.764V | 3.68% | Pass |
| 3.3V | 3.326V | 3.003V | 9.71% | Fail |
| 5VSB | 4.982V | 4.892V | 1.81% | Pass |
The +12V rail performs well, but the minor rails register high voltage drops with the 3.3V being the worst, by far, since it fails in all of our tests. Without the extra capacity that the ATX spec mentions, the 3.3V rail drops as low as 3V, registering up to 9.71% deviations! Clearly this is not what we expected in such an expensive power supply.
Turn-On Transient Tests
In the next set of tests, we measure 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.
Very good performance here. Only a tiny voltage overshoot at 5VSB.
Ripple Measurements
Ripple represents the AC fluctuations (periodic) and noise (random) found in the PSU's DC rails. This phenomenon significantly decreases the capacitors' lifespan because it causes them to run hotter. A 10°C increase can cut into a cap's useful life by 50 percent. 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 | 9.3 mV | 13.7 mV | 13.2 mV | 13.7 mV | Pass |
| 20% Load | 11.3 mV | 14.9 mV | 13.3 mV | 12.6 mV | Pass |
| 30% Load | 13.5 mV | 14.9 mV | 14.8 mV | 14.5 mV | Pass |
| 40% Load | 15.2 mV | 15.2 mV | 14.3 mV | 15.8 mV | Pass |
| 50% Load | 18.0 mV | 16.4 mV | 15.8 mV | 16.2 mV | Pass |
| 60% Load | 17.8 mV | 16.8 mV | 20.2 mV | 17.3 mV | Pass |
| 70% Load | 19.4 mV | 19.2 mV | 21.2 mV | 16.7 mV | Pass |
| 80% Load | 22.1 mV | 18.5 mV | 19.4 mV | 18.5 mV | Pass |
| 90% Load | 24.8 mV | 19.2 mV | 20.3 mV | 20.6 mV | Pass |
| 100% Load | 28.0 mV | 22.4 mV | 23.6 mV | 24.2 mV | Pass |
| 110% Load | 30.9 mV | 23.8 mV | 24.4 mV | 28.4 mV | Pass |
| Crossload 1 | 12.5 mV | 19.4 mV | 19.6 mV | 13.4 mV | Pass |
| Crossload 2 | 27.5 mV | 17.4 mV | 19.6 mV | 23.6 mV | Pass |
The ripple suppression is good. It might not be the best in this category, but you shouldn't forget that this unit doesn't utilize in-line caps in its modular cables, which are not the best available solution for low ripple since they make those cables bulky and difficult to work with.
Ripple At Full Load
Ripple At 110% Load
Ripple At Cross-Load 1
Ripple At Cross-Load 2
EMC Pre-Compliance Testing – Average & 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 close-by devices.
Electromagnetic Interference (EMI) stands for the electromagnetic energy a device emits, and it can cause problems in other close-by devices if too high. For example, it can be the cause of increased static noise in your headphones or/and speakers.
The transient filter does a good job, keeping the conducted EMI emissions low.
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