Antec HCG1000 Extreme 1000W PSU Review: Good Looks For $150

Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

Ιn these tests, we monitor the HCG1000 Extreme's response in several scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V, and 0.5A at 5VSB) is applied for 200ms as the PSU works at 20 percent load. In the second scenario, it's hit by the same transient load while operating at 50 percent load.

In the next sets of tests, we increase the transient load on the major rails with a new configuration: 15A at +12V, 6A at 5V, 6A at 3.3V, and 0.5A at 5VSB. We also increase the load-changing repetition rate from 5 Hz (200ms) to 50 Hz (20ms). Again, this runs with the PSU operating at 20 and 50 percent load.

The last tests are even tougher. Although we keep the same loads, the load-changing repetition rate rises to 1 kHz (1ms).

In all of the tests, we use an oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain within the ATX specification's regulation limits.

These tests are crucial because they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100 percent load of CPU/GPUs). We call these "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for a PSU with a capacity of less than 500W.  

Advanced Transient Response at 20 Percent – 200ms

VoltageBeforeAfterChangePass/Fail
12V12.082V11.995V0.72%Pass
5V5.012V4.886V2.51%Pass
3.3V3.323V3.204V3.58%Pass
5VSB5.088V5.036V1.02%Pass

Advanced Transient Response at 20 Percent – 20ms

VoltageBeforeAfterChangePass/Fail
12V12.082V11.929V1.27%Pass
5V5.012V4.866V2.91%Pass
3.3V3.323V3.182V4.24%Pass
5VSB5.088V5.040V0.94%Pass

Advanced Transient Response at 20 Percent – 1ms

VoltageBeforeAfterChangePass/Fail
12V12.080V11.985V0.79%Pass
5V5.011V4.865V2.91%Pass
3.3V3.323V3.180V4.30%Pass
5VSB5.088V5.042V0.90%Pass

Advanced Transient Response at 50 Percent – 200ms

VoltageBeforeAfterChangePass/Fail
12V12.077V12.012V0.54%Pass
5V5.009V4.876V2.66%Pass
3.3V3.320V3.195V3.77%Pass
5VSB5.057V5.003V1.07%Pass

Advanced Transient Response at 50 Percent – 20ms

VoltageBeforeAfterChangePass/Fail
12V12.075V11.983V0.76%Pass
5V5.009V4.856V3.05%Pass
3.3V3.320V3.173V4.43%Pass
5VSB5.058V5.008V0.99%Pass

Advanced Transient Response at 50 Percent – 1ms

VoltageBeforeAfterChangePass/Fail
12V12.074V11.969V0.87%Pass
5V5.009V4.854V3.09%Pass
3.3V3.320V3.171V4.49%Pass
5VSB5.058V5.004V1.07%Pass

#ALBUM_ 34965#

Voltage drops on the +12V and 5V rails were controlled well.

On the 5V rail, deviations were larger than we like to see. Meanwhile, the 3.3V rail was this PSU's worst performer. In most test scenarios, the 3.3V rail's voltage dropped below 3.2V.

Here are the oscilloscope screenshots we took during Advanced Transient Response Testing:

Transient Response At 20 Percent Load – 200ms

Transient Response At 20 Percent Load – 20ms

Transient Response At 20 Percent Load – 1ms

Transient Response At 50 Percent Load – 200ms

Transient Response At 50 Percent Load – 20ms

Transient Response At 50 Percent Load – 1ms

Turn-On Transient Tests

In the next set of tests, we measure the HCG1000 Extreme’s response in simpler transient load scenarios—during its power-on phase.

For our first measurement, we turn the power supply off, dial in the maximum current the 5VSB rail can handle, and switch the PSU back on. In the second test, we dial the maximum load the +12V rail can handle and start the PSU while it is in standby mode. In the last test, while the PSU is switched off, we dial in the +12V rail's maximum load before restoring power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V, and 5.5 V for 5V).    

There were no significant spikes or voltage overshoots to report. Still, the curves we recorded weren't the smoothest we've seen.

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  • richardvday
    I am very curious why so many 1000W or larger PSU's ? How many of these do they actually sell ? How many people need a 1000w PSU ? 500-600W seems the sweet spot that most people would need. I have an 850W that I have been kicking myself in the head for ever since really. I need 500W so my efficiency sucks, wasting energy.
  • totalinsanity4
    PSUs are actually most efficient when you're at about half load, so people with 500-600W loads will actually be seeing a slightly lower power bill with a 1000W PSU than, for instance, a 650W one
  • richardvday
    And idling ?
  • crmaris
    modern PSUs featuring LLC resonant converters also have good efficiency under light loads regardless capacity, given that their design is good. With LLC Burst Mode efficiency under light loads vastly improves.
  • test_purch1
    Test Automation comment 1535112055212