How to choose the right SMPS

How many watts do you need?

Start with the two parts that matter. The graphics card and the processor account for most of the draw. Everything else, drives, fans, memory, board, adds up to a much smaller number than people assume.

Take the card manufacturer's recommended system wattage as your floor, not your target. Then add headroom, because a supply running flat out all the time runs hot, gets loud, and ages faster.

Buying one size above what you need costs a little now and gives you room to fit a bigger card later without replacing the supply.

What does 80 PLUS actually tell you?

It tells you how much of the power drawn from the wall reaches your components rather than being lost as heat. Bronze, Gold and Platinum are steps up that ladder.

What it does not tell you is build quality, protection circuits or how the unit behaves when it fails, and those are the things that decide whether a failure is an inconvenience or an expensive afternoon. A certification is a floor, not a recommendation.

Independent test data matters more than the badge. Cybenetics publishes detailed measurements for a lot of the units sold here.

Which connectors does your graphics card need?

This is the detail that ruins build day. Older cards take one or two of the familiar eight pin PCIe connectors. Recent high end NVIDIA cards use a 12V-2x6 connector instead, and a supply without one needs an adapter, which brings its own cable management problem.

Count the connectors on the card's spec sheet, count what the supply ships with, and make sure the numbers match before you order. Also check the cable is long enough for your cabinet if the supply mounts at the bottom.

Modular or non modular?

Modular units let you attach only the cables you use. Non modular units have everything permanently attached, and the spare cables have to live somewhere inside the case.

It is a tidiness and airflow question rather than a performance one. In a small cabinet or one with a glass side, modular is worth the difference. In a large steel box that nobody looks inside, it is optional.

Why should you not save money here?

Because this is the part that fails badly. A cheap supply that dies quietly is the good outcome. The bad outcome sends a voltage spike through the motherboard, the drives and the card, and then you are replacing the whole machine.

Indian power makes this worse, not better. Voltage fluctuation, brownouts before a cut, and surges when the supply comes back are all normal here, and a thin unit with weak protection has to absorb all of it. Pair a decent supply with a UPS and most of that risk goes away.

From the counter

When a machine comes back with a random restart under load, the supply is the first thing we swap. It is the fastest test in the shop and it is right more often than any other guess.

The builds that never come back are the ones where the customer let us spend a bit more on the supply than they wanted to. That is not a sales line, it is what the repair bench looks like.

Frequently asked questions

Does a higher wattage supply use more electricity?

No. A supply delivers what the components ask for, not what it is rated for. A 850W unit powering a machine that draws 300W is drawing roughly 300W plus its losses, the same as a 600W unit would. The rating is a ceiling, not a consumption figure. What does change your bill is efficiency, which is why a Gold unit costs slightly less to run than a Bronze one at the same load.

Can I keep the supply from my old PC?

Only if it is a good unit, still within a sensible age, and has the connectors your new card needs. Supplies degrade. Capacitors age, especially in hot conditions, and a unit that has run for six or seven years in a Delhi summer is not the unit it was when new. If it came free with a cheap cabinet, it is not worth carrying over to a build you have spent money on.

What does the warranty length tell me?

More than the badge on the box does. A manufacturer offering a long warranty is making a bet on their own failure rate, and they price that in. Short warranties on power supplies are a signal. Also check how the warranty is actually serviced in India, because an international warranty with no local service centre means shipping the unit abroad at your cost, which nobody does.

Is the supply that comes bundled with a cabinet any good?

Almost never. Bundled units exist to make the package price look attractive, and the corners are cut in exactly the places that matter, which are the protection circuits and the quality of the components inside. They are acceptable for a basic office machine with no dedicated graphics card. They are not acceptable under a gaming card, and we will tell you that before you buy one.

How do I know if my supply is failing?

Random restarts under load, the machine shutting off during a game but running fine on the desktop, a burning smell, coil whine that has got noticeably worse, or a fan that has stopped spinning. None of these are certain on their own. If you see any of them, stop using the machine for anything you care about and bring it in, because continuing to run a failing supply is how the failure spreads to other parts.

Browse what we have in stock: 750W power supplies, 80 PLUS Gold power supplies, 80 PLUS Bronze power supplies.

Read next

• How to choose the right graphics card
• How to choose the right UPS
• How to choose the right cabinet

Written by Shreyansh Jain, who runs Get Right PC and is second generation in Nehru Place. Published 2026-09-24. Last updated 2026-09-24.