Do I need a UPS or surge protector for my mining PC?

A good surge protector is strongly recommended, and an uninterruptible power supply is worth considering if you run a node. Because a mining PC runs continuously, it is exposed to every power fluctuation, spike, and brownout your mains delivers over months. A quality surge protector defends the power supply and components from spikes for a modest cost and is sensible for any always-on machine. A UPS goes further, providing battery backup that lets the system ride out brief outages and shut down cleanly during longer ones, which protects against data corruption. This matters most if you run a node, where an abrupt power loss can damage the chain database and force a lengthy re-sync. For a mining-only PC, a surge protector is the practical baseline. For a node, the added safety of a UPS is usually worth it.