be quiet! SFX L 600W Power Supply review

1. Introduction2. Bundle & Cabling3. External4. Internal5. Methodology & Testing6. Closing Thoughts7. View All Pages

We review many power supplies, but its always a treat to get a new SFX unit into our labs for analysis. Today we take a look at the be quiet! SFX L, now available in 550W and 600W capacities. be quiet! have been behind many 80 Plus Bronze rated SFX power supplies in the past, but this new model is 80 Plus Gold rated and fully modular – a welcome addition to the line up for 2017.

The joy with SFX L is the longer chassis size – meaning larger fans can be incorporated inside. This will mean lower noise emissions. SFX L power supplies are diverse and can be used in a small form factor chassis and with an included adapter also inside a standard ATX case.

While be quiet! have two units available to buy in this specific range – we are looking at the SFX L 600W today. The other model is a smaller capacity 500W unit (SFX L 500W). There is a 3 year warranty with these units, which seems a little lower that I would expect considering many units are now protected by 7-12 year warranties.

BeQuiet! SFX-L 600W PSU Key Features:

• 80PLUS ® Gold certification with up to 92% power conversion efficiency
• Multi-GPU support with four PCIe connectors
• Full cable management for build flexibility and convenient usage
• Silent, temperature-controlled 120mm high-quality fan
• LLC, Synchronous Rectifier (SR) and DC-to-DC power conversion circuit design supports stability and efficiency
• High-quality Japanese capacitors for maximum reliability and operating life
• Powerful 12V-rail design for high stability and performance
• SFX-to-ATX adapter bracket allows flexible use with larger case sizes
• Black flat cables of up to 80cm for improved cooling
• 3-year manufacturer’s warranty
• Product conception, design and quality control in Germany

SFX L Power is available now – 500W for a recommended price of €109 / $119 / £95, or 600W for €129 / $145 / £115.

Review photography handled in house at KitGuru with a Leica S series medium format camera and S series prime lens. Please do not use any of the images within this review without express permission.

be quiet! box artwork is dark and very distinctive – the SFX L 600W box artwork maintains the company styling.

The rear of the box highlights the fan and cabling layout, but otherwise is quite spartan.

The power supply is shipped in the box alongside the cabling, user manual and adapter.

The power supply is protected inside a bubble wrap bag with only pieces of cardboard on the inner edges. Not the best packaging we have seen – I would expect more from be quiet! to be perfectly honest.

The power supply ships with a user manual, two sets of mounting screws and the ATX adapter panel. A regional power supply cable is also supplied.

All of the cables are ribbon style thin cables, ideal for cable management and routing within a new system build.

• 24-pin ATX (20+4) x 300mm long
• 4+4 pin ATX/EPS x 400mm long
• PCI-E x 400mm (to first connector)
• PCI-E x 500mm (to first connector)
• Peripheral SATA x 500mm (to first connector)
• Peripheral SATA x 300mm (to first connector)
• Peripheral HDD x 300mm (to first connector)

The be quiet! SFX L is nicely finished without any colours to annoy the enthusiast audience building into a windowed case. Paintwork is reasonably deep and resistant to scratches and fingerprints. The Satin black paintwork should satisfy anyone.

It measures 130 mm x 63 mm x 125 mm.

The large 120mm fan is hidden behind the black metal grill, with a company logo in the center.

One side of the power supply is home to the modular bay – all clearly labelled. It is impossible to mess up the cabling as the connectors are all different sizes.

The other side has a power connector, power switch and honeycomb air panel.

The be quiet! SFX L 600W power supply can deliver 50A via the +12V rail and 22A from both 3.3V and 5V rails.

This be quiet! power supply is using a fluid dynamic bearing fan – pretty common in 2017. It is a 120mm Globe Fan (Model S1201512MB) – rated 12V and 0.25A. It should be pretty quite, based on the technology.

Below - a High Resolution Gallery of the internal layout of the power supply.
If you dont see the gallery below, turn off your ad blocker.

be quiet! are using High Power as their OEM partner for this supply. We can see silk screened be quiet! logos on the PCB's so its clear they have a lot of control during the process. I was pleasantly surprised by how good the soldering was on the PCB, its a very clean and tidy looking design.

The High Power design utilises DC to DC converters to generate the +3.3V and +5V rails from the +12V rail. I was happy to see that unlike some of the be quiet! designs, they are using Japanese capacitors (Rubycon and Nippon Chemi Con) in the primary and secondary stages. The main primary Rubycon capacitor is 85C rated, not 105C. Not a huge deal really as Rubycon make great caps, but worth noting.

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.

We test ambient temperatures at 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		-12V
	A	V	A	V	A	V	A	V	A	V
75W	1.09	3.30	1.47	5.03	4.92	12.18	0.50	5.01	0.20	-12.03
150W	2.09	3.28	2.97	5.02	10.02	12.16	0.50	4.99	0.30	-12.04
300W	4.30	3.27	6.00	5.00	20.58	12.07	1.00	4.96	0.30	-12.05
450W	6.57	3.26	8.48	4.98	31.79	12.00	1.50	4.88	0.30	-12.04
600W	9.94	3.25	12.20	4.96	41.78	11.95	2.50	4.86	0.30	-12.04

Load regulation is quite good, holding within around 3%.

be quiet! SFX L 600W	Maximum Load
	666W

The number of the beast! we managed to get 666 watts out of the unit before it shut down safely.

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
590W	1.0	3.30	1.0	5.01	46.0	11.94	0.2	-11.98	0.50	4.95
145W	12.0	3.24	15.0	4.95	2.0	12.20	0.2	-12.02	0.50	4.93

The supply passed the cross load test, although the results show quite a variation on the rails.

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
75W	5	5	5	5
150W	5	5	5	5
300W	5	5	10	10
450W	10	10	25	15
600W	10	10	40	20

Ripple suppression rates very highly with all the rails falling well within industry tolerances. At full load the +12V rail hits 40mV which is a great result for an SFX L unit. +3.3V and +5V rails hit a peak of 10mV at full load. These are very commendable.

Efficiency (%) 230V
75W	87.45
150W	89.87
300W	92.21
450W	91.87
600W	90.69

Efficency is very good and it exceeds 80 Plus Gold levels across the board. It peaks at just over 92% at 50% load.

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 Refrigerator
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)
75W	29.3
150W	30.5
300W	33.2
450W	34.5
600W	36.8

The power supply is quiet when delivering under 300 watts. At higher loads the fan spins up to compensate and its audible when delivering around 500 watts of power. Overall however, and even when delivering a full 600 watts of power, the fan is actually never that intrusive.

Temperature (c)
	Intake	Exhaust
75W	35	42
150W	35	47
300W	37	52
450W	41	56
600W	44	59

The large fan helps move a lot of cool air across the internal components and as such the thermals are very good, even when tasked with a high load.

Maximum load	Efficiency
666W	90.2

At 607W the FSP power supply drops to 90.2%. This is not a viable ‘real world’ situation, but its interesting nonetheless.

The be quiet! SFX L 600W power supply has impressed me. Its technically very capable and it doesn't exhibit any glaring faults to raise concern. The price point around £115 seems quite competitive as well, which helps when making a buying decision. These are inherently more expensive than a standard ATX supply.

When it comes to SFX power supplies, the fans are generally very small, loud and intrusive. I find it hard living with an SFX power supply on any level, so have never often used them for any of my own builds. Small 90mm fans are annoying.

be quiet! have extra space inside this SFX L chassis to incorporate a larger 120mm fan, and their choice of Fluid Dynamic bearing ensures that long life, and low noise levels prove to be key selling points.

Efficiency exceeds 80 Plus Gold in our tests, and voltage regulation is without a problem. Ripple suppression is not the best we have seen in recent months, but the figures are low enough to fall well within industry rated specifications. For an SFX based design they are actually very very good indeed.

While the OEM partner is High Power, it is clear be quiet! have had a lot of input into the design, their logo is silk screened all over the design and we like the fact they have not taken short cuts. It is fully modular and all the cables are thin ribbon style, ensuring that system builds are as neat and tidy as possible and air flow is maximised.

This particular supply is designed for use inside small form factor chassis but the included ATX adapter gives it added versatility. You may need some cable extensions for this to work properly inside larger cases. be quiet! have kept the cable lengths rather short so bear this in mind.

The only real niggle I have is the very short 3 year warranty offered with this unit. Many power supply warranties now are between 7 and 12 years, so 3 years does raise an eyebrow. Corsair have an SFX L unit available right now with a 5 year warranty for instance, so this might cause a few people to wonder if the be quiet! unit is a good long term investment. be quiet! have thankfully made the wise move to adopt high grade Japanese capacitors in the design, but unfortunately some of these are 85c rated, not 105C – including the primary Rubycon capacitor. Its not likely to be a problem long term, but if you are running a system in a hot climate with limited chassis airflow, it is worth factoring into a final buying decision.

You can buy the be quiet! SFX L 600W power supply from Overclockers UK for £114.95 inc VAT HERE.

Discuss on our Facebook page, over HERE.

Pros:

• quality finish externally.
• technically very solid.
• good ripple.
• efficiency exceeds 80 Plus Gold.
• fully modular.
• quiet.
• All Japanese capacitors.
• 120mm Fluid Dynamic Bearing Fan.
• Versatile design – works with ATX via the included adapter.

Cons:

• minimal 3 year warranty.

KitGuru says: The be quiet! SFX L 600W power supply is very attractive, quiet versatile and technically proficient. The minimal 3 year warranty is rather poor however.

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