Corsair HX1200i 1200W ATX 3.1 Power Supply: features, specs and who it suits

The Corsair HX1200i (model CP-9020281-NA) is a fully modular ATX power supply for desktop PCs. It is aimed at builders who want a power supply that meets the current ATX 3.1 standard, runs quietly, and offers software control over its fan and protection settings. Here is what the listed features mean.

What "fully modular" means

On a fully modular unit, every cable detaches from the power supply, including the main motherboard cable. You connect only the cables your build needs, which typically leaves less clutter inside the case, improves airflow and makes tidy routing easier. Corsair presents this as a way to make clean builds simple. Spare cables stay out of the way until a later upgrade needs them.

ATX 3.1 and PCIe 5.1

Corsair says the unit is Intel ATX 3.1 certified, supporting the PCIe Gen 5.1 platform. In general terms, the ATX 3.x standards were written for modern graphics cards, which can briefly draw much more power than their average. Corsair says the design resists these transient power spikes. The same standard covers the 12V-2x6 high-power graphics connector that recent cards use, so check the box contents or the manual for the cable your card needs. Corsair's description also mentions ATX 3.0 and PCIe 5.0 compliance, which sits in the same family of standards.

80 Plus Platinum efficiency

80 Plus is a certification for how efficiently a power supply converts mains AC into the DC your PC uses. Platinum is a higher tier, and in general it means less energy is lost as heat. A cooler-running unit can use a slower fan, which helps with noise. Efficiency figures depend on the load, so the certification describes performance at set test points.

Fan and noise

The 1200W unit uses a 140mm fluid dynamic bearing fan, which Corsair says is extremely quiet and long-lasting. Fluid dynamic bearings generally reduce friction and noise compared with simpler sleeve designs. There is also a Zero RPM mode: at low and medium loads, the fan switches off entirely for near-silent operation. At higher load, the fan spins up. Corsair's description also lists Japanese 105°C-rated electrolytic capacitors and a ten-year warranty.

iCUE software control

With Corsair iCUE software, you can create custom fan curves, monitor power settings and switch between single-rail and multi-rail overcurrent protection (OCP). Multi-rail splits the output into separately protected lines, while single-rail pools them. Which suits you depends on your hardware. The listing also mentions Modern Standby support, which Corsair says wakes the computer faster and uses less power in sleep.

Size and weight

It measures about 7.9 x 5.9 x 3.4 inches (around 20 x 15 x 8.6 cm) and weighs about 5.3 lb (2.4 kg).

Who it suits

It suits builders of high-end systems, such as a powerful graphics card plus a multi-core processor, who want headroom at 1200W. It also suits anyone who values a near-silent PC and a tidy interior.

What to check before you buy

• Total power: add up the draw of your processor, graphics card and other parts, and leave headroom.
• Graphics card connector: confirm the cable that comes with the unit matches your card.
• Case fit: check that your case supports a standard ATX power supply of this depth.
• Cables: keep modular cables with the unit that came with them. Cables are not always interchangeable between brands.
• Installation: follow the manual, and unplug the PC from the wall before working inside it.

The short version

• A 1200W fully modular ATX power supply from Corsair.
• Intel ATX 3.1 certified, with PCIe Gen 5.1 support.
• 80 Plus Platinum efficiency and a 140mm fluid dynamic bearing fan with Zero RPM mode.
• iCUE software for fan curves, monitoring and OCP mode.
• Ten-year warranty, per Corsair.

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