ASRock Steel Legend SL-1200GW 1200W Power Supply Review

Conclusion and Verdict

With the recent focus on AI, we’re starting to see bigger and larger power supplies on the market. So why do you need a big PSU for AI? Well, you need a big power supply mainly because AI hardware — particularly GPUs and accelerators draw a huge amount of power. Many AI workstations (or servers) run multiple GPUs in parallel (2–8 or more in one system), so the total power demand can easily reach beyond 2,000+ watts. Even smaller setups with consumer GPUs (like the GeForcer RTX 5090, etc.) can pull 575W per card, and multiple cards add up quickly.

What makes the SL-1200GW stand out from the rest, is the fact that it’s one of the first sub-$200 all-white 1200W power supply that’s certified Cybenetics PLATINUM with LAMBDA A+ ratings. Both of these ratings are recognised certifications for power supplies that high-light performance, build quality, reliability and noise level. For more information about Cybernetics and LAMBDA go here.

The build quality of power supply is very good, and uses 100% Highly Reliable Japanese Capacitors, which gives it superior power efficiency. You also get excellent stability via the powerful +12V single rail @ a whopping 100A, giving you a total power output of up to 1200W.

I love the flat modular cables as it allows me to use the minimum amount of cables necessary to get the system fully operational. It also means you’ll get more air-flow within your chassis. The cables are clearly labelled and easy to plug in. The package also includes some cable ties and velcro straps for cable management.

The PSU defeatures dual native 12V-2×6 (16-pin) connectors, a feature normally found on high-end power supplies made for workstations. It comes with flat 12V-2×6 (16-pin) cables with a Dual Color Design rated up to 600W. The dual color design allows you to see and make sure the cables are fully plugged in between the graphics card and the power supply.

The whole power supply is cooled by a large 135mm striped axial Fluid Dynaming Bearing fan, and features ASRock’s iCool Intelligent Fan Control Mode for quiet operation. It’s ASRock’s own take on the Zero RPM function. And to top it all off, ASRock have included an impressive 10-Year warranty for peace of mind.

During our tests, we installed the SL-1200GW on to our test rig which is comprised of an AMD Ryzen 9 9950X processor and has a max TDP of 170W, along with the GeForce RTX 4080 SUPER with a TBP of up to 320W. At 100% load, just these two components alone consumes well over 488+ Watts.

At full load, the +12V line was very stable with only a slight drop from +12.096V to +11.904V. For the +5V line, it was rock solid at +5.080V during full load, with no fluctuations at all. The +3.3V line also remained unchanged at +3.296V.

Based on our tests, I’m more than happy with the results and I’m pleased with the overall performance and stability. The ASRock Steel Legend SL-1200GW is indeed a very solid power suppy.

You can buy the ASRock Steel Legend SL-1200GW 1200W Power Supply for around USD $199 – https://amzn.to/4mEHTxs

Final Thoughts:

ASRock have now added an-all white 1200W sub-$200 modular power supply to its Steel Legend series. It not only offers excellent stability thanks to its powerful +12V single rail at 100A, but also comes with 80 PLUS GOLD ceritficatiosn, along with Cybenetics PLATINUM and LAMBDA A+ ratings. What’s more, it supports the latest ATX3.1 and PCIe 5.1 standards, plus you’ll also get an impressive 10-Year warranty for peace of mind.

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