PC Power & Cooling Silencer 910W ATX PSU
Simulated Load Testing
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To provide accurate and consistent results in all of our PSU testing, Overclock3D uses professional grade DCÂ electronic load equipment capable of placing a sustained load of 3690w across a total of six rails (including +5vsb and -12v) on the PSU! This is achieved by using a combination of SunMoon and Analogic electronic load equipment which allow us to adjust amperage loads in increments as small as 0.01A while also measuring voltage and wattage readings on-screen.
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During today’s tests, we will be placing the PC Power & Cooling Silencer 910 under 25%, 50%, 75% and 100% load levels at both room temperature and inside a hot box regulated to a temperature of around 50°C. Additional ‘Cross Load’ and a ‘Max Load’ tests will also be performed under these conditions to simulate how the PSU reacts to heavily uneven loads as well as running above its specified output.
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PCP&C Silencer 910W @ Room Temperature
 DC Watts
 Exhaust
(Low)
227w
33.6°C
(Med)
454w
40.7°C
5.12v
(High)
679w
42.3°C
(Full)
903w
42.5°C
(x-load)
160w
32.1°C
(x-load)
911w
41.8°C
(MAX)
1084w
46.4°C
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The Silencer 910 gets off to a good start with a show of solid voltage stability during the standard load tests(1-4) across all rails. If I wanted to be picky I could say that it would have been nice for PCP&C to set the idle voltages a tad lower as 3.40v and 12.29v is beginning to push on the ‘high’ side – even though it is of course WELL within ATX specs. The cross-load tests (5 & 6) are also handled reasonably well with the only worrying output being the -12v rail. ATX specs give this rail a tollerance level of ±10%, but in test 6 this manages to hit -14.47v obviously falling well outside of spec. However, as I’ve said many times before, these cross-load scenario’s are highly unlikely to be seen in normal usage so this really isn’t so much of a problem.
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Efficiency is also very good across the board with the unit managing between 88-90% in all of the standard tests and anything from 82% to 87% in our custom cross-load and max load tests. This obviously helps to keep temperatures inside the unit at manageable levels (with less energy being wasted as heat) and in most cases the delta between Intake and Exhaust temperatures rarely exceeds 14°C.
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PCP&C Silencer 910W @ 50c
 DC Watts
 Exhaust
(Low)
227w
58.1°C
(Med)
454w
57.8°C
5.12v
(High)
679w
58.8°C
(Full)
899w
65.9°C
(x-load)
160w
58.4°C
(x-load)
911w
68.3°C
(MAX)
1093w
74°C
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Re-running the tests again, only this time with an ambient temperature of 50°C really put the cooling inside the Silencer to the test. Normally I wouldn’t comment on the noise output of the unit as the load testing equipment is kitted out with numerous large 240v fans that can easily drown out the sound of Metallica playing live in the next room. However, in tests 4, 6 and 7 the ‘Silencer’ ramped up the fan speed so much that it was clearly audible above the load testers. Silent? I think not.
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Aside from the noise, very little changed in any of the other departments. Efficiency dropped by an average of 1% across the board and voltages dropped by 0.01-0.02v. So it’s quite clear to see that the Silencer is well equipped for delivering its full 910w load (and above) in the Sahara desert if needed.
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One final thing to note before I move on is just how powerful that 12v rail is. Although not an official test I pushed the rail as far as it would go before the PSU powered down. 90A was the magic number. Impressive indeed.
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PCP&C Silencer 910w Scope Results @ 50°C
(Low)
(Med)
(High)
(Full)
(x-load)
(x-load)
(MAX)
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For the last part of the testing I analysed the ripple on the +3.3, +5 and +12v rails using a Rigol 25Mhz 400MSa/s oscilloscope. All readings were taken while the Silencer 910 was installed inside the 50°C hot box to provide us with worst case scenario results.
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And here are some interesting results indeed! Keeping in mind that ATX spec states that DC output noise/ripple should remain below 50mV(pp) on the +3.3v / +5v rails and below 120mV(pp) on the +12v rail it’s not long at all before the Silencer 910 falls outside of specification. By test 3 the +3.3v rail is at 62mV and the +5v rail at 74mV with the +12v rail just about managing to say inside spec at 104mV. When running at a full 911w load in test 4 the +12v rail also goes outside of spec hitting 146mV with the other rails also increasing significantly too.
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This is not what I was expecting from PCP&CÂ at all. Convinced something else was amiss somewhere else in the test setup, I swapped out the Silencer with another PSUÂ tested earlier in the week to see if the results differed from the original ones. They didn’t. OK so it’s not the load testing equipment, maybe its a faulty cable on the Silencer? Nope. As far as I could see, all cables and connectors appeared to be fine and connected well to the load tester.
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So who knows. I refuse to believe that these are the actual results having seen much cleaner results from JonnyGuru. But then again these occasional spikes which are bumping up the Vpp results up might not be something that every scope will pick up on. I’ve asked PCP&CÂ for some insight but as yet have not received a response. Faulty PSU, faulty results, interference from alien life forms. Who knows.
