Seasonic Platinum Fanless 520W Power Supply Review

1. Introduction2. Seasonic Platinum Fanless 520W (Bundle & Cables)3. Seasonic Platinum Fanless 520W (External)4. Seasonic Platinum Fanless 520W (Internal)5. Seasonic Platinum Fanless 520W (Super High Res Gallery)6. Testing Methodology7. Closing Thoughts8. View All Pages

Seasonic have been releasing a fantastic range of power supplies this year including the high end X-Series and the price competitive G-Series. Today we are looking at something really special however- a fanless, modular Platinum certified supply targeted at those people who want to build a silent system.

Special Features –

• 80PLUS® Platinum Certified Super High Efficiency
• Full Modular Cabling Design
• Fanless- 0dBA
• Patented DC Connector Module with Integrated VRM [Voltage Regulator Module]
• DC to DC Converter Design
• Conductive Polymer Aluminum Solid Capacitors
• Highly Reliable 105°C Japanese Aluminum Electrolytic Capacitors
• Tight Voltage Regulation [±2%]
• Active Power Factor Correction [99% PF Typical]
• High +12V Output
• Gold Plated High Current Terminals
• Dual Sided PCB Layout
• Ultra Ventilation [Honeycomb Structure]
• Multi-GPU Technology Support
• All-in-One DC Cabling Design
• Easy Swap Connector
• Universal AC Input [Full Range]
• 7 Years Warranty

The Seasonic Platinum Fanless 520W arrives in a stylish box with an artistic viewpoint of the supply itself.

The bundle includes a user manual, warning notice (detailing air flow as this is a passive design), mounting screws, a bag of cable ties, modular bag of cables and a case sticker. The power supply itself is wrapped inside a soft felt bag for protection during shipping.

The felt bag opens up and between this is a regional specific power plug. Inside two pouches are the modular cables which are listed above. For a 520W rated unit, there are more than we would have expected. They are all 18 AWG with only the main M/B connector being sleeved, all the rest are flat ribbon style to improve airflow.

The Seasonic Platinum Fanless 520W Power Supply ships with a warning notice wrapped around the chassis. As this unit is passively cooled it is important to ensure that the warm air can easily escape.

There are also several vents on the side panels to further improve cooling.

One side of the power supply is fully vented with a power switch and connector set to the side.

The other side of the chassis contains all the connectors for the modular cables. At the side of this panel is a venting hole to further help with heat removal.

Seasonic Platinum Fanless 520W Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	20A	20A	43A	0.5A	2.5A
Total Power	100W		516W	6W	12.5W
	520W

The upper side of the chassis has some venting holes, however it should be installed with this side facing down. The Seasonic Platinum Fanless 520W can deliver 43A on the +12V output, for 516Watts of the total power.

No fan in this unit, but there are plenty of rows of heatsinks to help with cooling proficiency. The Seasonic Platinum Fanless 520W  is a synchronous unit with a DC-DC design in the secondary stage.

As we have discussed before, this means that the power supply is for all intents and purposes a 12V unit. The +3.3V and +5V outputs are produced by two smaller power supplies which are connected to the +12V  rail.

This is an ideal construction to maximise efficiency levels.

This supply has two X capacitors, four Y capacitors and ferrite coils. The primary stage of the unit uses a Hitachi 105c capacitor rated 330 µF x 420 V. The switching section uses four IPP50R250CP MOSFETS. Electrolytic capacitors in the secondary are also high grade Japanese capacitors from Rubycon and Chemi-Con.

On this page we present some super high resolution images of the product taken with the 24.5MP Nikon D3X camera and 24-70mm ED lens. These will take much longer to open due to the dimensions, especially on slower connections. If you use these pictures on another site or publication, please credit Kitguru.net as the owner/source.

Additional technical assistance: Peter McFarland and Jeremy Price.

Correctly testing power supplies is a complex procedure and KitGuru have configured a test bench which can deliver up to a 2,000 watt DC load. Due to public requests we have changed our temperature settings recently – previously we rated with ambient temperatures at 25C, we have increased ambient temperatures by 10c (to 35c) in our environment to greater reflect warmer internal chassis conditions.

We use combinations of the following hardware:
• SunMoon SM-268
• CSI3710A Programmable DC load (+3.3V and +5V outputs)
• CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• Extech Power Analyzer
• Extech MultiMaster MM570 digital multimeter
• SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa)
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB
	A	V	A	V	A	V	A	V
110W	1.02	3.35	1.02	5.03	8.04	12.06	1.00	5.05
220W	2.05	3.34	2.03	5.03	16.03	12.05	1.00	5.04
305W	3.01	3.34	3.05	5.02	22.08	12.04	1.50	5.03
410W	4.02	3.33	4.06	5.02	30.21	12.03	2.00	5.01
515W	5.03	3.32	5.08	5.01	38.34	12.03	2.50	5.01

Voltage regulation is exceptional, holding almost at reference results throughout.

Seasonic Platinum Fanless 520W	Maximum Load
	641.5W

We managed to load the PSU with 641.5W watts before it shut down gracefully. That really is an incredible result for such a unit.

Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly.

Cross Load Testing	+3.3V		+5V		+12V		-12V		+5VSB
	A	V	A	V	A	V	A	V	A	V
493W	1.0	3.34	1.0	5.03	40.0	12.03	0.2	-12.05	0.50	5.04
153W	15.0	3.32	15.0	5.01	2.0	12.05	0.2	-12.03	0.50	5.03

The PSU coped exceptionally well, even when loaded with 40A on the 12V rail. These are some of the best results we have seen to date.

We then used an oscilloscope to measure AC ripple and noise present on the DC outputs. We set the oscilloscope time base to check for AC ripple at both high and low ends of the spectrum.

ATX12V V2.2 specification for DC output ripple and noise is defined in the ATX 12V power supply design guide.

ATX12V Ver 2.2 Noise/Ripple Tolerance
Output	Ripple (mV p-p)
+3.3V	50
+5V	50
+12V1	120
+12V2	120
-12V	120
+5VSB	50

Obviously when measuring AC noise and ripple on the DC outputs the cleaner (less recorded) means we have a better end result. We measured this AC signal amplitude to see how closely the unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
110W	5	10	15	5
220W	10	10	15	5
305W	10	10	20	5
410W	10	10	25	5
515W	15	15	30	5

Ripple suppression is exceptional, with both +3.3V and +5V output peaking at 15mV at full load. The +12V output held between 15mV and 30 mV. Truly exceptional results.

Efficiency (%)
110W	91.6
220W	93.3
305W	93.5
410W	92.2
515W	91.2

Efficiency results are excellent, peaking at around 93.8% (at 260W). This drops off to just over 91% at full load. Fantastic results yet again.

We take the issue of noise very seriously at KitGuru and this is why we have built a special home brew system as a reference point when we test noise levels of various components. Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on components we are testing. It also brings us slightly closer to industry standards, such as DIN 45635.

Today to test the Power Supply we have taken it into our acoustics room environment and have set our SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself.

As this can be a little confusing for people, here are various dBa ratings in with real world situations to help describe the various levels.

KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refridgerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 Player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet takeoff/Gunshot (close range)
160dBA – Instant Perforation of eardrum

Noise (dBA)
110W	/
220W	/
305W	/
410W	/
515W	/

Just in case you haven't worked it out yet, yes this supply is passively cooled… emitting no noise at all.

Temperature (c)
	Intake	Exhaust
110W	35	37
220W	37	42
305W	40	50
410W	45	55
515W	47	62

The efficiency of the unit is great so the temperatures don't rise much even as load increases.

Maximum load	Efficiency
641.5W	89.0

Pushing the PSU above its rated limits generates an efficiency level of around 89.0%. This is not a viable ‘real world’ situation, but its interesting nonetheless.

As we mentioned earlier in the review, Seasonic have been consistently releasing quality power supplies this year.

The Seasonic Platinum Fanless 520W is not only a fantastic power supply, it is arguably their best unit ever, and one of the finest available to the enthusiast audience.

We can find not a single flaw with this unit. Load regulation is class leading with hardly any fluctuation at all, even during intensive cross loading tests.

Additionally ripple/noise suppression of the Seasonic Platinum Fanless 520W is exemplary and one of the best we have reviewed this year.

The stand out aspect is obviously the fact that this unit doesn't emit any noise, thanks to the fanless design.

When we look at the efficiency results it is actually hard to believe there is no fan running in this unit. Passively cooled power supplies tend to have reduced efficiency levels, due to high internal temperatures.

UK availability of the Seasonic Platinum Fanless 520W is due in the coming week, however US prices are around $150, so we would expect to see this unit for around the £120 inc vat mark.

Obviously we would expect a price premium considering the modular design, silent operation and platinum efficiency, but to say we are impressed with this unit is an understatement. It is truly exceptional, especially when you factor in that we pushed it to deliver over 640 watts.

Pros:

• silent.
• impressive efficiency.
• rock stable.
• ripple suppression.
• modular.
• bundle.
• can deliver over 640 watts.
• 7 year warranty.

Cons:

• expensive.

Kitguru says: Sure it's expensive, but the Seasonic Platinum Fanless 520W is one of the best PSU designs of all time and one of the finest options available to enthusiasts, plus it has an impressive 7 year warranty and there really is no competition in its class.

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