Super Flower Leadex Platinum 550W Power Supply Review

by - 4 years ago


Introduction & Packaging

Leadex platinum 550w

Super Flower may not be the first name you think of when you think of power supplies, but time and time again they’ve proven they can make some of the best-performing power supplies on the market, but not only that, they also create some of the best looking PSUs, all while maintaining competitive prices. With all that in mind, I’m very excited to see their latest unit, the Leadex Platinum 550W, in the eTeknix office today.

As the name would suggest, this is an 80 Plus Platinum rated unit, that means that the unit won’t be wasting as much of your electricity, or the money you spend on your electricity build, before it gets to your system, saving you a little extra money over the time you use it; certainly no bad thing being a little more economical and green.

Equipped with a fully modular design, all the latest safety features you would expect, high levels of efficiency, a premium quality semi-passive 135mm fan cooling design, and rather uniquely, a set of LED lights in the cable connectors, adding a little extra flair to your system build.


  • 100% Full Modular Cabling Design For Easy Cable Management
  • 80 PLUS ® Platinum Certified, 90% 92% 89% Efficiency At 20% 50% 100% Rated Load
  • Full Range Auto Voltage Detection Design 100V~240V (Active PFC)
  • Comply With ATX 12V. V2.2, EPS 12V. V2.91 & SSI EPS 12V. V2.92 Specification
  • Comply With Energy Star Standard & EuP (Energy Using Products) Regulation
  • Over Voltage Protection / Over Current Protection / Over Power Protection / Short Circuit Protection / Under Voltage Protection / Over Temperature
  • Protection
  • Support All Intel/AMD Multi-Core CPU & ATX/BTX Compatible Motherboards
  • Support NVIDIA® SLI™ & ATI CrossFireX™ High Performance Graphic Card
  • Patented Easy To Use & Install Crystal Clear Cube Connectors with LED
  • More than 2,000 times On/Off test
  • Unleaded Green Materials with RoHS/WEEE Compliance
  • Perfect For Professional & High Performance Gaming System


  • Dimensions: 150 x 86 x 165 mm (W x H x D)
  • Wattage: 550W
  • Fan: 135 mm DBB(automatic control, semi-passive)
  • Colour: Black (power supply, fan)
  • Fully Modular Design
  • Efficiency: max. 92% (115V), 80 Plus Platinum certificate
  • Active PFC
  • Safety: cTUVus/TUV/CB/CE/FCC/C-Tick/BSMI/RoHS/CCC
  • Partcode: SF-550F14MP black (UK)


  • 1 x 20+4-Pin ATX12V/EPS12V
  • 1 x 4+4-Pin ATX12V/EPS12V
  • 3 x 6+2-Pin-PCIe
  • 7 x SATA
  • 4 x 4-Pin-Molex
  • Warranty: 5yr

The packaging is quite understated, giving us a stylish logo and the main spec, but nothing to indicate the design of the PSU.


Around the back, a few close up pictures of the various components, as well as a lot of technical information, such as the Japanese capacitors and the fully modular cabling design.


There’s not exactly a lot of extras in the box, just a few thumb screws and the owner’s manual, but you really don’t need much more anyway.


The cables come neatly packed away in a protective case, which is great for those who don’t need all the cables right now, but you may in the future when you upgrade and they’ll be neatly stored away.


Finally, you’ll also find the mains cable, which is nice and thick, making it durable, and comes with a good length.



A Closer Look – Exterior

First impressions of the Leadex Platinum are superb, it’s a brilliant looking design with a really unique fan grille. What is shocking is that it’s black, given that the box is white and the small images on the box are of a white unit, this could be confusing to some consumers.


The paint work is gorgeous, it’s not quite matte, it’s not quite glossy, but it looks great either way. The contrasting white fan blades certainly add to the appeal too.


The base of the unit, certainly nothing much to see here, just a blank panel.


The main specifications sticker shows us that we’ve got a very powerful 45.8A on the +12V rail, so we know it’s going to be great for those overclocking their CPU and/or GPU.


Down the other side, a fairly understated by stylish Super Flower logo.


Virtually edge to edge ventilation around the back, so that fan should have little issues with shifting heat out of the unit. It’s also nice to see a master power switch for those times you need your PC completely powered down.


This is by far the best part, those funky 3×3 grid connectors. The clear plastic design has a built-in white LED lighting and they just look a bit cooler than the stock connectors we’ve seen time and time again. There’s also a very handy auto and eco mode switch, which toggles the fans hybrid cooling mode on.



The cables are of a good quality and all the more power heavy cables are thickly braided and round. The connectors are colour coded on the hardware side of things, although I’m not sure why and all black, or keeping with the clear theme of the PSU end connectors would have been preferred; for me personally at least.


All the peripheral cables are flat-type, which makes them a heck of a lot easier to route and better yet, they have more uniform black headers on the hardware ends of each cable.



A Closer Look – Interior

It certainly looks like Super Flower took their time with this one, as there’s a lot of hardware in here, but it’s beautifully spaced out and organized, which should help with the overall airflow and cooling greatly.DSC_4187

As we said before, the PSU has all Japanese capacitors, all rated to 105C. The main bulk capacitor is capable of up to 400v at 560uF, so I suspect we may see this unit pull more wattage than it is rated for.


There’s a huge bank of secondary voltage caps too, which again leads me to think this unit is going to be more capable that it says on the box; not that this is a bad thing.


The EM/Line filtering stage. All neat and tidy in the corner and away from any major hardware. Hopefully, the adequate spacing on the components should help reduce any noise and ripple in the power delivery.


There are a few smaller daughter boards which come vertically from the main PCB. This will help greatly with cooling each of them and there are even a few smaller finned heat sinks on each to help even further with the cooling.


There’s also a large cooling fin on the higher voltage hardware. Overall, the layout and interior design is very well executed and better than what I’m used to seeing in units rated for this wattage.


The fan is a very nice quality Globe Fan RL4Z B1252512M. The 135 mm DBB fan has automatic control and semi-passive functionality, so it should be nice and quiet.



Test Procedure

At eTeknix we take the power supply testing procedure very seriously and have invested a lot of resources into acquiring the appropriate testing equipment. For all power supply reviews we test the power supplies with dedicated power supply testing equipment. This means we are able to get the most accurate results from our testing as opposed to using software benchmarks (such as OCCT) or multi-meter readouts which are broadly inaccurate.


Our test machinery is as follows:

  • Sunmoon SM-5500ATE Active Load Tester (1200W rated)
  • Stingray DS1M12 USB Oscilloscope
  • Voltcraft DT-10L laser tachometer

The eTeknix test procedure involves:

  • Testing each power supply at 20/40/60/80/100% load (with balanced load across all rails) and measuring PFC (power factor correction), efficiency (actual power divided by power “pulled at the wall”) and voltage regulation (deviance from expected voltages of 3.3/5/12 on the main rails).
  • Measuring ripple with an oscilloscope at 20/40/60/80/100% load.
  • Measuring fan speed after a stabilisation period of five minutes at each load scenario using the Voltcraft DT-10L laser tachometer and a reflective strip on the fan.
  • Testing each power supply’s OPP (Over Power Protection) mechanism and seeing how many watts each power supply can deliver before shutting down

Other things to consider are that

  • We recognise that a single yellow 12 volt cable can provide only 6 Amps before overheating (which corrupts voltage regulation and efficiency) and so we used an adequate number of cables for each power supply to ensure there is not efficiency loss from poor cables selection
  • Our Sunmoon SM-5500ATE power supply tester is not capable of testing more than 300W on each of the 12 volt rails so where a power supply provides more than 300W on a 12 volt rail that power is distributed over multiple 12 volt rails on the load tester. For example a power supply with one 12 volt rail supplying 750 watts would be spread equally over three 12 volt rails on the load tester, a power supply with two 450W 12v rails would be spread over four 12v rails on the load tester, two 225W 12v rails for each of the 12v rails on the unit.
  • We use the same time scale and horizontal millivolt scale on our oscilloscope for all ripple tests, that is a 20ms T/DIV (horizontal) and a 0.02 V/DIV (vertical) meaning the scale is from -80mV to +80mV, ATX spec dictates that the 12v rail must fall within 150mv of ripple and the 3.3/5 within 50mv so that scale allows us to include both 150 and 50mV peaks. (Some older PSU reviews use different scales which were later ditched as the visual representation they give is inadequate, in these reviews written measurements are provided only).
  • Deviance is the terminology used to represent the way voltages diverge from the expected values

Efficiency, PFC and Voltage Regulation

Voltage Regulation

To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviance of each rail from its expected voltage.

sf550 voltage regulation

Wow, these results are very impressive, with tight voltage regulation on all rails, and well within what we would call a good margin, and actually better that most PSUs on the market.

Power Efficiency

Power efficiency is measured by calculating actual supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test 230v power supplies.


sf550 power efficiency

Efficiency is right on the money here, falling comfortably within the Platinum rating and that’s great for those who don’t want to be wasting more power than they need to while running their rig.

Power Factor Correction

Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. The aim of PFC is to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source – Wikipedia).sf550 pfc

PFC results are very promising, there was a little drop around 40%, but even then the results are still very high and show us that this is a high-quality PSU.



Noise and Ripple can easily be measured by an oscilloscope. These show how much voltage fluctuation there is on a particular rail. We tested the rail stability of the 3.3 volt, 5 volt and 12 volt rails using an identical time and millivolt scale for all graphs. millivolt ripple is measured by the peak to peak size of the voltage curve.


Sample Ripple Graph

The latest ATX 12 volt version 2.3 specifications state that ripple from peak to peak must be no higher than 50 millivolts for the 3.3 volt and 5 volt rails, while the 12 volt rail is allowed up to 120 millivolts peak to peak to stay within specifications. Millivolt figures are stated to the closest increment of 5 given their variability.

 Load (%)   3.3V Ripple   5V Ripple   12V Ripple 
 20  2.8  4  4.4
 40  3.6  3.6  5
 60  4.2  5  6.6
 80  4.2  5  7.4
 100  5  5.5  8.2

The ripple performance may be the best we’ve ever seen! Those figures are so low, it’s likely going to be a long time before we see another PSU perform better. If you’re looking for clean power delivery, this is as good as it gets.

3.3 volt @ 100%

sf550 3

5 volt @ 100%

sf550 5

12 volt @ 100%

sf550 12


Over Power Protection and Max Wattage

Power supplies often quote as having various protection mechanisms such and the most important of these is Over Power Protection. In our testing we crank up the power draw until the power supply either shuts down (meaning the OPP mechanism is present and working) or blows up (meaning it is either not present or not working). We then note the maximum power consumption before the power supply shut down (or blew up).

sf550 opp

Once again we’re seeing seriously impressive results, as this 550W power supply was able to draw a staggering 817W before it powered down, that’s a huge amount above the rating, so you should have virtually no issues with power draw spikes causing system instability.


Fan Speed

When testing in a power supply laboratory it is difficult to take fan noise readings as the noise from the Sunmoon test equipment and air conditioning corrupts everything. The next best thing in our circumstances was reading off the fan speed with a tachometer to get an idea for the noise. The ambient temperature during testing held constant at 22 degrees, with 1 degree of variation. Each power supply had a consistent time period of 5 minutes to stabilise between each load scenario. 

In my experience the following general relationships apply between noise levels and fan speeds, though it can vary greatly between the type of fan used.

  • Below 800 RPM – Inaudible/Silent
  • 800 to 1000 RPM – Barely audible
  • 1000 – 1200 RPM – Audible but still quiet
  • 1200 – 1400 RPM – Moderately noisy
  • 1400 – 1800 RPM – Noisy
  • 1800 RPM or higher – Intolerable

sf550 fan As if all that high performance wasn’t impressive enough, The fan managed to say well below 900 RPM even at full load, keeping the unit virtually silent. This was even more apparent in hybrid fan mode, as the fan didn’t spin at all, even after spending 30 minutes at full load, nothing. The ambient temperature was 22c, so once you’ve got this in a chassis and your room is warmer, the fan will kick in when it’s needed, but it’s unlikely you’ll ever hear this power supply running, even in active cooling mode.sf550 hybrid fan


Final Thoughts


The Super Flower Leadex Platinum 550W Fully Modular 80 Plus Platinum Power Supply can be picked up from most major retailers, and is currently available from Overclockers UK for a very reasonable £74.99. While that may seem a lot for a PSU of this power output, it’s an absolute bargain for a Platinum unit, with many manufacturers making 80 Plus Gold rated units for the same price!


Super Flower makes some of the best power supplies in the world and their Leadex Platinum 550W is a prime example of just how great they can be. To have the high-end performance of a much more expensive unit at a wattage and price range that would suit virtually any single GPU system configuration, with headroom for dual graphics cards on more modern and efficient GPUs is simply fantastic.

The performance figures of this unit just keep on getting better and better. Reliable voltage regulation, exceptionally low ripple (some of the lowest we’ve ever seen!), fantastic cool with virtually no noise and a hybrid/passive cooling mode that’s even quieter, great efficiency that will save you money in the long run, and finally, let’s not forget that it was able to exceed 800W power draw!

Picking the right PSU for your system can be tricky, knowing which wattage or efficiency to get for your budget, but with this unit, it’s a no-brainer. The price is good, the performance is fantastic, the overall design, build quality and aesthetics are all premium grade. With the added bonus of those gorgeous cables, as well as their LED block fittings, Super Flowers widely trusted hardware testing and competitive 5-year warranty the Leadex Platinum 550W ticks every box for what we look for in a great PSU.


  • Competitive price
  • Superb build quality
  • Great aesthetics
  • Platinum efficiency
  • Virtual silent operation
  • Impressive OPP
  • Extremely low ripple
  • 5-year warranty


  • None
Super Flower Leadex Platinum 550W Modular Power Supply Review

Super Flower Leadex Platinum 550W Modular Power Supply Review

Thank you OCUK for providing this review sample.

Article Index

  1. Introduction and Packaging
  2. A Closer Look - Exterior
  3. A Closer Look - Interior
  4. Test Procedure
  5. Efficiency, PFC and Voltage Regulation
  6. Ripple Testing
  7. OPP and Max Wattage
  8. Fan Speed
  9. Final Thoughts
  10. View All

Author Bio

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2 Comments on Super Flower Leadex Platinum 550W Power Supply Review

  • Avatar tomekkk1 says:

    Couple of confirmations of things we can read in this test, plus one small issue found:
    • Bulletproof build without the doubt – every detail of PSU case has been made neatly, using proper solid materials.
    • Full set of aesthetic cables, easy to manage them as I wish, long enough
    for most of cases – connectors are pretty solid on both sides.Full set of aesthetic cables, easy to manage them as I wish, long enough
    for most of cases – connectors are pretty solid on both sides. Cables finishings are in finest quality, once connected they stays secure & tight in the sockets. Bag for unnecessary cables is an nice add-on too;
    • Stability – the voltages are really like frozen: idle, moderate load under full load, or quick changing load – doesn’t matter, still great stability;
    • Stone cold – now will be something quite interesting: I’ve got this unit in NZXT Noctis 450 PC Case, inside of integrated shroud. The fan is set in “ECO” (hybrid semi-passive mode), fan hole is located on top (I didn’t fit it up side down by purpose), where is only 2-3mm distance to the top of the shroud. Could say the heat must be generated inside, resulting that fan will by running very often. Nothing like that… To be honest it didn’t run even once yet. It is stone cold. The lowest case fan (with very reduced speed), located at the front of PC case surely makes the air moving towards PSU a bit – and this is the only ventilation there. Really the fan in this Power Supply is just like additional bonus – been given, but we never needed to use;
    • The only small issue is SATA supply cable. As most of the PC cases are
    now designed with PSU located at bottom I found this cable is designed
    other way round – like for PSU’s located at top of the case. That means
    if you connecting two or more drives (I have three HDD’s currently)
    firstly the lowest Drive needs to be connected using farthest plug we have on the lead, than next one above etc.
    After connect the last top one, rest of the cable needs to go back down to PSU –
    makes this area unnecessary busier than we need, which tat is only thing to consider if we have smaller / very low budget PC case.

    Generally – it is really silly to compromise own choice buying cheapest PSU. And now it is a lot easier to make right decision – we can reach for not very expensive Hi-End Power Supply in the price of Mid-Class. Cannot choose better…

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