Quick Dive: What You’ll Learn

I’ve been building PCs for over a decade, and I’ve used everything from Corsair AX1600i to cheap 80+ whites that died in a year. When I first got my hands on the Super Flower Leadex III 1000W 80 Plus Gold, I was skeptical. Super Flower isn’t a household name in North America – they’re an OEM that makes units for brands like EVGA and NZXT. But this particular model? It’s something special. After 8 months of daily use, I’m ready to share the no-BS details.

Bottom line upfront: The Leadex III 1000W offers near-flagship electrical performance at a mid-range price. It’s quieter than most Gold units, and the cable quality is actually better than some Platinum PSUs I’ve tested. But there’s a catch with the native 12VHPWR cable – I’ll get to that.

First Impressions & Unboxing

The box is compact compared to other 1000W units. Inside, the PSU is wrapped in foam, and the pouch for cables is velour – nice touch. The unit itself is 150mm deep, shorter than many 1000W competitors (most are 160-180mm). That’s a godsend for small cases like the Fractal North or Meshify C.

I noticed the fan grille uses a honeycomb pattern with circular corners – it’s not just for looks; it reduces turbulence noise. The fan is a 135mm Hong Hua bearing (HA13525H12F-Z). While 135mm is slightly smaller than the typical 140mm, the blade design is aggressive. Initial spin test: silent.

Build Quality & Internal Architecture

What’s under the hood?

After briefly peeking through the fan (don’t void your warranty, kids):

  • Primary capacitor: Two 420V 390μF Nippon Chemi-Con caps (105°C rated).
  • Secondary caps: All Japanese Chemi-Con or Rubycon, mostly solid polymers.
  • Topology: Full-bridge LLC resonant + synchronous rectification + DC-DC converters. Standard for efficient Gold units.
  • Soldering: Clean, with no cold joints. I’ve seen worse in Corsair RMx units.

The heat sinks are adequate for 1000W, but I wish the primary side had slightly more mass – though it never tripped in my 450W gaming load.

Electrical Performance & Ripple

I measured ripple with an oscilloscope (Rigol DS1054Z) at 80% load on a dummy load. Results:

RailRipple (mV p-p)Intel Spec
+12V22 mV120 mV max
+5V15 mV50 mV max
+3.3V18 mV50 mV max

That’s excellent – some Platinum units push 30 mV on 12V. Voltage regulation stayed within 0.5% under crossload. The hold-up time is around 18ms, which is fine for most UPS systems. I was honestly impressed.

One nitpick: The 12V ripple has a tiny spike around 50mV when the PSU is cold (under 10°C). I live in a cold basement, so I noticed it. Not a dealbreaker, but worth mentioning.

Cable Management & Connectors

The Leadex III is fully modular, and the cables are individually sleeved with paracord – not the stiff nylon found on older units. The 24-pin motherboard cable has two 4+4 EPS12V (CPU) cables, and four 6+2 PCIe cables. For modern GPUs, that’s plenty.

But here’s the catch: the native 12VHPWR (12+4 pin) cable that comes with the unit is rated for 600W, but its 16AWG gauge is thinner than the 14AWG used by Corsair. I tested it with a 4090 drawing 450W and the cable got warm (45°C). Not dangerous, but I’d recommend using three separate 8-pin PCIe cables with the adapter instead – actually, the unit doesn’t include a 12VHPWR adapter. Weird omission.

Noise Levels & Fan Behavior

In eco mode (half-bridge, fan turns off below ~30% load), the unit is completely silent until you hit about 300W. At 450W, the fan spins at ~700 RPM, barely audible. At full load (1000W), fan noise reaches 38 dBA – noticeable but not obnoxious. The fan curve is more aggressive than the EVGA G6 (which uses a similar platform). If you’re noise sensitive, the Leadex III is still one of the quietest Gold units.

I accidentally covered the fan intake once (poor case placement), and the unit got hot (~65°C inside) but still didn’t shut down. Thermal protection works well.

How It Stacks Against Competitors

I’ve used the Corsair RM1000x (2021), Seasonic Focus GX-1000, and EVGA SuperNOVA 1000 G6. Here’s my take:

ModelRipple (12V)Noise @ 500WPrice (USD)My Rating
Super Flower Leadex III 1000W22 mV~25 dBA$1609/10
Corsair RM1000x (2021)28 mV~28 dBA$1808.5/10
Seasonic Focus GX-100035 mV~32 dBA$1707.5/10
EVGA SuperNOVA 1000 G620 mV~27 dBA$2008/10

The Leadex III is the best value – better ripple than the RM1000x, quieter than the Seasonic, and cheaper than all three. But the EVGA G6 has slightly better ripple and a 10-year warranty (vs 7 years for Super Flower).

Who Should (and Shouldn’t) Buy This PSU

You should buy it if:

  • You’re building a high-end gaming rig with a 4090/7900 XTX and want excellent stability.
  • You care about silent operation under normal loads.
  • You’re on a budget but won’t compromise on electrical performance.

You might want to skip it if:

  • You need native 12VHPWR support (buy an adapter separately, or get a unit with one).
  • You want a 10-year warranty (this one has 7).
  • You have a case with PSU clearance less than 150mm – but that’s rare.

FAQ – Real Questions, Real Answers

My 4090 draws 450W – will the single 12VHPWR cable from this PSU handle it safely?
The cable is 16AWG and rated for 600W, but I observed 45°C at 450W. It’s safe, but if you’re pushing 600W transient spikes, I’d use the provided three 8-pin PCIe cables with a 12VHPWR adapter (not included). The voltage drop is minimal, but heat buildup might be a concern in poorly ventilated cases.
Is the eco mode fan actually silent? I’ve heard some units have coil whine at low loads.
On my unit, zero coil whine under any load. The eco mode works – fan stops below 250W. But one caveat: if your system idles at high power (like an HEDT platform with multiple GPUs), the fan may cycle on/off frequently. Super Flower uses a decent hysteresis, but it’s not perfect.
How does the 135mm fan compare to 140mm fans in terms of lifespan?
Hong Hua bearings are reliable – I’ve seen them run 50k+ hours. The 135mm actually spins faster to move the same air, so it may wear out slightly sooner than a 140mm at same airflow. But with the low-load eco mode, the fan barely spins most of the time. I’d expect 7-10 years of typical use.
I want to run this PSU in a SilverStone SST-SX1000 – is it compatible?
The Leadex III is ATX, not SFX. So no, it won’t fit in a small form factor case unless you have a custom mount. For ITX builds, look at the 750W SFX version (if they make one).

This review is based on my personal experience with the retail unit purchased in 2024. Electrical measurements were done with a calibrated oscilloscope. I have no affiliation with Super Flower.