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Ripple Measurements

To learn how we measure ripple, please click here.

The following table includes the ripple levels we measured on the SSR-750FX's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V, and 5VSB).

Swipe to scroll horizontally

Test	12V	5V	3.3V	5VSB	Pass/Fail
10% Load	8.9mV	6.0mV	8.2mV	5.7mV	Pass
20% Load	12.7mV	6.1mV	8.5mV	5.9mV	Pass
30% Load	15.2mV	6.3mV	8.5mV	6.1mV	Pass
40% Load	17.1mV	7.8mV	10.4mV	6.5mV	Pass
50% Load	18.3mV	7.8mV	9.1mV	6.5mV	Pass
60% Load	20.2mV	10.4mV	10.6mV	7.2mV	Pass
70% Load	21.9mV	11.4mV	11.6mV	8.4mV	Pass
80% Load	23.0mV	11.6mV	11.8mV	9.4mV	Pass
90% Load	26.2mV	13.1mV	13.1mV	9.8mV	Pass
100% Load	27.9mV	13.2mV	14.6mV	11.6mV	Pass
110% Load	28.6mV	15.4mV	15.9mV	12.2mV	Pass
Cross-Load 1	12.3mV	11.3mV	9.4mV	8.2mV	Pass
Cross-Load 2	27.2mV	10.6mV	12.8mV	9.2mV	Pass

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The addition of filtering caps on the modular cables, along with a good overall design, enable impressive ripple suppression. Seasonic still doesn't achieve Super Flower levels, but it'd be silly to complain. Even under 110% load, the +12V rail doesn't exceed 30mV, while the minor rails stay below 16mV in the worst-case scenario.

Ripple Oscilloscope Screenshots

The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01 V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.

Ripple At Full Load

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Ripple At 110-Percent Load

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Ripple At Cross-Load 1

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Ripple At Cross-Load 2

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Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

7 Comments Comment from the forums

none77

Thank you for the detailed review.
In the transient response test
Advanced Transient Response at 50 Percent – 200ms
the +3.3 pass.

Reply
BugariaM

As always, here are the most detailed reviews on the PSU.
Thank you and keep it up!

The only thing that is not quite clear to me. What is the criterion for voltage drop in % to get PASS/FAIL in "Advanced Transient Response Tests"?

You declare that:

"In all tests, we measure the voltage drops." The voltages should remain within the ATX specification's regulation limits. "

For ATX 2.2 we have:

12v - 10%
5v - 5%
3.3v - 5%
5VSB - 5%

However, looking at your reviews, there are often situations where, at <5%, the power supply gets the FAIL mark and vice versa, some at >5% receive PASS

Why is this happening?
Reply
BugariaM

Sorry, a typo
Of course for 12v - 5%
Reply
Aris_Mp

the limit is 5% however the voltage rails of the PSUs' under test in the majority of cases aren't at the nominal voltages, but higher, so even with 5% deviation voltages go don't bellow the limits that the ATX spec sets (11.4V, 4.75V, 3.14V). Only if a rail goes below those voltage levels it fails. The 5% is just an indication that the ATX provides to specify the voltages above.
Reply
BugariaM

Now everything became clear to me.
Thank you.
Reply
fredlaso

Dell Inspiron 5675 Desktop, PSU (power supply unit), upgrade. Would this PSU compatible with Dell Inspiron 5675 Desktop. It came with 460W I would like to replace it with PSU between 650 to 750W. I tried at Dell forums but cannot get a clean link which one would be compatible.

I would greatly appreciate if someone could help me out. Thank you kindly in advance:

http://en.community.dell.com/support-forums/desktop/f/3514/t/20019321?pi21953=1#21018407
http://en.community.dell.com/support-forums/desktop/f/3514/p/20024419/21031446#21031446

System Comp,:
Compatible Power Supply needed for Inspiron 5675 Gaming Power Supply
Specs:

AMD Ryzen 7 1700X 3.4GHz Octa-Core Processor
8GB 2400MHz DDR4 RAM
1TB 7200 RPM Hard Drive
AMD Radeon RX 580 8GB GDDR5 Graphics Card
DVD+RW Drive
Dual Band WiFi 802.11ac + Bluetooth 4.1
Windows 10 Home (64-bit)
460 Watt Power Supply w/ Polar Blue LED
Includes: Dell KB216 Wired Keyboard + Dell MS116 Wired Mouse
Ports:
6x USB 3.0
1x USB 3.1 Type-C Gen 1
2x USB 2.0
1x Audio Combo Jack
1x 3-in-1 Media Card Reader
1x P/S 2
1x 7.1 Channel Audio Out
Expansion Slots:
3x 3.5" bay
2x 2.5" bay
2x PCIe x1
2x PCIe x16

http://en.community.dell.com/support-forums/desktop/f/3514/t/20019321?pi21953=1#21018407
http://en.community.dell.com/support-forums/desktop/f/3514/p/20024419/21031446#21031446
Reply
paulinosaka

My Seasonic Platinum began failing under load after only 10 months. Paid cash here in Japan at Joshin - couldnt find reciept - honestly never thought I would need it ever. Seasonic would not help me.?
REPLY
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