Should I replace my decade-old Corsair AX850 PSU before it fails?

An 850W supply is still plenty for many modern systems. The main reasons to upgrade would be needing additional wattage, wanting a native ATX 3.0/3.1 connection for a newer high-end GPU, or wanting the peace of mind that comes with fresh capacitors and a current warranty. Replacing it solely to save electricity probably won't pay for itself.

If you do replace it, never reuse the modular cables from the AX850. Modular PSU connectors can look identical while using different pinouts, even between models from the same manufacturer. Use only the cables supplied with the new power supply, and replace the unit immediately if it has suffered heavy dust buildup, unusual noises, burning smells, or repeated shutdowns.

If the AX850 is working normally and your current hardware doesn't need more power, there's no urgent reason to replace it. It was a high-quality unit, and many people continue using similar supplies for well over a decade. Keep it in its current system unless you start seeing crashes, unexpected restarts, electrical noise, or you upgrade to hardware with higher power demands.

A failure doesn't usually destroy the rest of the computer; most power supplies simply shut down or cause a crash and reboot. Still, components age over time, and a ten-year-old unit is more of an unknown—especially with a power-hungry graphics card. If downtime would be costly or you're about to install a modern high-end GPU, replacing it beforehand is reasonable, but you don't necessarily need a $230 1000W model. A reputable 850W ATX 3.0 or 3.1 supply is often enough and may cost considerably less.