DC Load Regulation and AC Ripple
DC Output Load Regulation
To simulate real world and maximum loading conditions, the Seasonic Platinum Series 660W PSU was connected to the load testers and supplied with a constant 115 VAC. In this test we are interested in seeing how well a PSU can maintain the various output voltages while operating under different loads.
The ATX12V V2.2 tolerance for voltages states how much each output (rail) is allowed to fluctuate and has tighter tolerances now for the +12V outputs. I have also included a second table of expanded tolerances (±1% to ±6%) for reference.
The following tables list the DC voltage results for the PSU while operating on 115 VAC, 60 Hz.
As you can see, the Platinum 660W PSU produced excellent load regulation on all of the outputs across a broad range of loads. The three primary outputs (+3.3V, +5.0V and +12V) stayed within ±2% of their target values – very good!
AC Ripple and Noise on the DC Outputs
The amount of AC ripple and noise present on the DC outputs was checked using a digital oscilloscope. This AC component may be present in the KHz range where most switching power supplies operate or it may be more prevalent at the 60 Hz line frequency. We adjust the O-scope time base to look for AC ripple at both low and high frequencies. The ATX12V V2.2 specification for DC output noise/ripple is defined in the ATX12V Power Supply Design Guide.
Ideally we would like to see no AC ripple (repetitive) or noise (random) on the DC outputs – the cleaner the better! But in reality there will always be some present. I measured the amplitude of the AC signal (in millivolts, peak-to-peak) to see how well the power supply complied with the ATX standard. The following table lists the ripple/noise results during all of the load tests for the main output voltages of interest.
The Seasonic Platinum 660W power supply exhibited very good AC ripple suppression on all of the primary outputs and stayed well below the recommended values, even at full load.
F, bought the 1000watt
F, bought the 1000watt version back in May and it came with the ugly colored modular cables.
hello there, I have a
hello there, I have a question, since you got that colored modular cables, did you report that to seasonic and did you make a request of being provided with black cables for it? just wondering because if I will be getting one, I might get colored cables too.
Love me some Seasonic.
Love me some Seasonic.
Seasonic is always my first
Seasonic is always my first choice when I am in the market for a new psu. Not only are the psu’s excellent, but so too is their customer service.
Just got two of these and
Just got two of these and both of them had coils noise and one also coil whine. Sent them back, very disappointed. (Tested on several platforms and the noise was persistend, even on professional APC UPS)
If your unit produces coil
If your unit produces coil whine or noise, the fix is often to enter BIOS and make sure all power saving options are turned on.
Of course, if yours is defective that is another issue.
I had coil noise even when
I had coil noise even when using a paperclip to start the PSU. It’s more annoying than any fan.
How about the Seasonic
How about the Seasonic SS-760XP2 (Platinum 760) in this series? How’s the performance, any issues, coil noise or fan loudness or performance issues?
Seasonic Platinum 760 – SS-760XP2 https://seasonic.com/product/platinum-760/