DC Load Regulation and AC Ripple
Testing Methodology
Establishing an accurate load is critical to testing and evaluating a PC power supply. PCPerspective’s power supply test bench can place a precise DC load on the PSU under test. Each power supply is tested under controlled, demanding conditions up to its maximum rated load (at 40ºC). Our current suite of tests includes:
• DC Load Regulation
• AC Ripple and Noise
• Efficiency
• Differential Temperature
• Noise
The SilverStone Platinum ST1000-PT power supply was evaluated on both features and performance. A full range of equipment was used to test the power supply under controlled load conditions.
• (2) CSI3710A Programmable DC load (+3.3V and +5V outputs)
• (4) CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• (2) 200W Precision resistor load bank (+12V5 and +12V6)
• Switchable precision resistor load bank (-12V and +5VSB)
• Agilent 34401A digital multimeter (Accuracy ±0.0035% vDC)
• Extech 380803 Power Analyzer (Accuracy ±0.5% of full scale)
• DS1M12 "StingRay" digital oscilloscope (20M S/s with 12 Bit ADC)
• Powerstat Variable Autotransformer, 1.4 KVA, 0-140 VAC
• Extech Model 407738 digital sound level meter (Accuracy ±1.5 dB)
The following cables/connectors were used to connect the power supply to the PCPerspective power supply test equipment.
• (1) 20+4 pin ATX
• (2) 8-pin EPS/ATX12V
• (6) 6-pin PCI-E
• (6) SATA
• (6) Molex
DC Output Load Regulation
To simulate demanding and maximum loading conditions, the ST1000-PT power supply was connected to the load testers and supplied with a constant 120 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. We have included a second table of expanded tolerances (±1% to ±6%) for reference.
The following tables list the DC voltage results for the SilverStone Platinum Series 1000W PSU while operating on 120 VAC, 60 Hz.
The power supply produced very good voltage regulation on all of the DC outputs with the three main rails staying easily within ±2% of the recommended ATX guidelines; well within SilverStone’s claimed ±3%. A very good start.
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 ST1000-PT power supply also exhibited very good AC ripple and noise suppression with the results staying far below the ATX recommended guidelines, even at full load when delivering a 1000W to the DC outputs. Looking good.
Silverstone is pretty
Silverstone is pretty quality. I buy their PSUs exclusively and recommend them to my friends.
Decent review but could be
Decent review but could be better.
Just “eyeballing” the modular connectors using the Hi-Res pictures on Silverstone’s own web site suggests some of the modular cables can be plugged into connectors they are not meant to be connnected to.
Why would anyone do this? Hey! It happens. People get rushed to play with “the new toy” or they don’t look carefully at the power supply in a dark PC case or “tightly packed Pc case” and end up forcing the cable into the wrong connector while cursing out the “bleeping computer”.
Next, this power unit has cables with “those obsolete connectors” on them. What do I mean? Those obsolete 4-pin floppy power connectors. It is hard to tell from the pictures here and on Silverstone’s web site if “those obsolete connectors” are on their own modular cable or attached to the end of some other cable.
Finally, like another commenter once pointed out here a few weeks ago. “Is it Haswell certified?”
Hey Lee! Step up your product reviewing game. This review seemed like too much of a “softball” that was tossed at Silverstone. Maybe some “investigative journalist” shhould look into the potential relationship between Silverstone, PCP and Lee? Just sayin….
ATX or peripheral power
ATX or peripheral power cannot be plugged into PCIe power (which is blue) due to the connecter being different and its color coded anyway. Cables on the end of the psu are hardly the only thing that can be plugged into something wrong if you are stupid and force it so its really a non issue.
If you looked at the pictures on the review its obvious that 4 pin floppy is attached to each of the molex harnesses.
Almost all of silverstones PSUs were stated as haswell certified back when that news ware relevent. It would be incredibly stupid if they were to go backwards. If you actually read the review and looked at the voltage charts provided and were aware of the of the conditions of haswell compatability (No 12V rail running out of spec) which this PSU is well within you might realise that this isnt even as issue.
In answer to your question
In answer to your question about the possibility of accidentally plugging one of the modular cables into a connector it was not intended for, please see the edits I added to page 3 and page 6. Thanks for pointing this out.