I've had my PC for about 18 months and want to protect it from electrical surges, especially because replacing its components would be very expensive. It has an RTX 5080, Ryzen 7 9800X3D, 64GB of RAM, and a 1000W power supply. I've seen recommendations suggesting around 3000 joules of protection for a system like this, but most UK surge-protected extensions seem to be rated below 900J, with the highest option I've found rated at 2700J. How useful are these ratings in practice, and what do people typically use for surge protection in the UK?
4 Answers
UK mains power is generally quite stable, so catastrophic surge damage is uncommon, but a reputable surge-protected extension is still a reasonable precaution. Masterplug, Brennenstuhl, and similar established brands are commonly used. Don’t expect any plug-in protector to reliably stop a direct lightning strike, though.
A UPS can be more useful than a surge-protected extension on its own. It provides battery backup during a power cut, giving the PC time to shut down cleanly and helping protect against brief interruptions and voltage problems. Choose one with enough capacity for the computer and monitor, and make sure it has suitable surge protection as well.
The joule rating isn’t a simple requirement based on your PC’s wattage. It indicates how much surge energy the device can absorb before its protection components wear out. A decent 900J unit can still help with smaller transient spikes; a higher rating generally gives more capacity, but it doesn’t make the device lightning-proof. Surge protectors also degrade over time and should be replaced periodically.
The most important protection is a good-quality, correctly installed PSU and modern household wiring. If the house has very old wiring or a dated fuse box, getting the electrical installation checked is more worthwhile than obsessing over a particular joule number. For a normal UK home, a reputable surge-protected extension is usually sufficient for basic peace of mind.

Would a 900J-rated protector still offer useful protection against smaller spikes?